Chloral copolymers

ABSTRACT

AN ADDITION COPOLYMER OF CHORAL AND AT LEAST ONE COMONOMER OF THE FORMULA R3-N=C=X WHEREIN X IS OXYGEN OR SULFUR AND R3 IS A NON-SUBSTITUTED HYDROCARBYL RADICAL. CHLORAL IS COPOLYMERIZED WITH ONE OR MORE ISOCYANATE, ISOTHIOCYANATE, DIISOCYANATE, DIISOTHIOCYANATE OR KETENE COMPOUNDS TO PRODUCE COPOLYMERS WHICH ARE NONFLAMMABLE AND WHICH CAN BE MADE INTO A VARIETY OF USEFUL, SHAPED OBJECTS. THE PROCESS OF MAKING THE COPOLYMERS INVOLVES PREPARING A HOMOGENEOUS MIXTURE OF MONOMERS AND POLYMERIZATION INITIATOR AT A TEMPERATURE ABOVE THE THRESHOLD POLYMERIZATION TEMPERATURE OF THE MIXTURE COOLING THE HOMOGENEOUS MIXTURE BELOW THE THRESHOLD POLYMERIZATION TEMPERATURE AND MAINTAINING THE HOMOGENEOUS MIXTURE QUIESCENT DURING THE POLYMERIZATION.

United States Patent Int. Cl. (108g 1/12, 9/18 U.S. Cl. 260--67 TN 32 Claims ABS'I'RACT OF THE DISCLOSURE An addition copolymer of chloral and at least one comonomer of the formula R -N=C=X wherein X is oxygen or sulfur and R is a non-substituted hydrocarbyl radical. Chloral is copolymerized with one or more isocyanate, isothiocyanate, diisocyanate, diisothiocyanate or ketene compounds to produce copolymers which are nonflammable and which can be made into a variety of useful, shaped objects. The process of making the copolymers involves preparing a homogeneous mixture of monomers and polymerization initiator at a temperature above the threshold polymerization temperature of the mixture cooling the homogeneous mixture below the threshold polymerization temperature and maintaining the homogeneous mixture quiescent during the polymerization.

CROSS-REFERENCES TO RELATED APPLICATIONS This application Ser. No. 886,739, filed Dec. 19, 1969, now US. Pat. No. 3,668,184, granted June 6, 1972 which is a continuation-in-part of my application Ser. No. 731,- 622 filed May 23, 1968, which in turn was a continuation-in-part of my applications Ser. No. 580,217, filed Sept. 19, 1966 and Ser. No. 558,631 filed June 20, 1966, the last three of which are now abandoned.

BACZKGROUND OF THE INVENTION Field of the invention This invention relates to a new class of copolymers of chloral with at least one isocyanate, isothiocyanate, diisocyanate, diisothiocyanate or ketene and process for their preparation.

Description of prior art Applicants US. Pat. 3,454,527 issued July 8, 1969, discloses homopolymers of chloral prepared by a process which involves preparing a uniform mixture of chloral and polymerization initiator at a temperature above the threshold polymerization temperature of the mixture, cooling the uniform mixture below the threshold polymerization temperature, and maintaining the mixture quiescent during the polymerization.

US. Pat. 3,265,665 issued to Mantell et al. on Aug. 9, 1966 discloses copolymers of formaldehyde and isocyanates by a polymerization process which involves cooling to low temperatures. Chloral is not disclosed nor suggested and quiescent conditions are not maintained during the polymerization process.

Takida et al., Kobunski Kagaku (Chemistry of High Polymers, Japan) 22, 463-472, July 1965, show the copolymerization of chloral with phenyl isocyanate at low temperatures but do not use quiescent polymerization conditions. Their process produced only crumbly, powdery products.

DESCRIPTION OF THE INVENTION This invention is directed to addition copolymers of chloral and at least one comonomer selected from the group consisting of (II) (III) X is selected from the group consisting of oxygen and sulfur;

R and R alike or different and separately or jointly, are selected from the group consisting of (1) monovalent groups selected from the group consisting of hydrogen, cyano, lower alkoxycarbonyl, and unsubstituted and substituted hydrocarbyl and hydrocarbyloxy in which any hydrocarbyl moiety is of 1-18 carbon atoms selected from the group consisting of alkyl, cycloalkyl, aryl, aralkyl and alkaryl, and any substituent is selected from the group consisting of lower alkoxy, fluorine, chlorine, bromine, and iodine; and (2) divalent groups selected from alkylene of 2 to 7 carbons;

R is selected from the group consisting of non-substituted and substituted alkyl and cycloalkyl of up to 18 carbons, aryl of 6-18 carbons and alkaryl and aralkyl of 7-24 carbons, any substitution being selected from the group consisting of fluorine, chlorine, bromine, iodine, nitro, cyano, phenylazo, NY -OY, SY,

in which Y is lower alkyl or phenyl; and

R is selected from the group consisting of non-substituted and substituted alkylene, alkarylene, aralkylene, cycloalkylene, alkylenebis(cycloalkylene), alkylenebis(arylene), arylene, arylenebis(alkylene) of up to 18 carbons and anthraquinonylene, any substitution being selected from the group consisting of fluorine, chlorine, bromine, iodine, nitro, cyano, phenylene, NY OY, SY,

in which Y is lower alkyl or phenyl.

Either one or a plurality of ketenes, isocyanates, isothiocyanates, diisocyanates, and/or diisothiocyanates may be reacted with chloral.

In the above definition of R and R preferred hydrocarbyl moieties are allyl of l to 18 carbon atoms, cycloliowe; alkyl, phenyl, naphthyl, benzyl, tolyl, mesityl and ury \it \ll I'll/m...

in which a represents the mol percentage of chloral units and 100a represents the mole percentage of ketene units in the copolymer and R and R are as defined above. Each copolymer molecule contains at least four chloral units.

The isocyanate, isothiocyanate, diisocyanate and diisothiocyanate copolymers of this invention are addition polymers which may generally be represented by Forin which b and c represents the mol percentage of chloral units and 100-b and l-c represent respectively the mol percentage of isocyanate and diisocyanate units in the copolymer, and R and R are as defined above. Each copolymer molecule contains at least four chloral units.

It will be understood that more than one compound of Formulas I, II and :III can be polymerized with chloral in the process of this invention. The invention thus includes an addition copolymer of chloral and at least one comonomer selected from at least two of the groups or Formulas, I, II and III.

The ketene, isocyanate, isothiocyanate, diisocyanate and diisothiocyanate copolymers of this invention also include branched and crosslinked products in which both N=O=X groups of compounds of Formula II polymerize with chloral to form network structures, for which no simple recurring structural formula can be drawn.

The copolymers of this invention contain from 1 to 99.9 mol percent of chloral and in general have better thermal stability than polychloral. Copolymers having about 50 to 99.9 mol percent of chloral are a preferred class. Even more preferred are copolymers having about 80 to 99.9 mol percent of chloral. The copolymers may range from soluble, fusible products to insoluble, infusible products depending on the specific ingredients used and their proportions.

Copolymers containing from about 80 up to 99.9 mol percent of chloral and a corresponding 0.1 up to about 20 mol percent of comonomer are usually insoluble in common organic solvents such as methanol, ethanol, acetone, benzene, toluene, chloroform, carbon tetrachloride, tetrachloroethylene, ethyl acetate, etc., and are substantially infusible at temperatures up to their decomposition point. Where the chloral content of the copolymer is below about mol percent the products are generally soluble and fusible. It is to be noted however, that the 80 mol percent of chloral content does not always form the line of demarcation. The specific comonomer used, that is, isocyanate, ketene, diisocyanate, etc. has an effect on the characteristics of the final polymer. For example in chloral-isocyanate copolymers having less or more than 80 mol percent of chloral, some may be soluble and infusible, or fusible and insoluble, depending on the particular comonomer isocyanate used to make the copolymer.

The process of preparing the copolymers comprises cryotachensic polymerization. This involves forming a homogeneous mixture of the monomers, an anionic polymerization initiator, and 0 to 99% by weight of the total composition of an aprotic solvent, at a temperature above the threshold polymerization temperature of the mixture, cooling the homogeneous mixture below the threshold temperature whereby polymerization occurs, and maintaining the mixture at such lower temperature until polymerization subsides. A critical aspect is that the polymerization mixture is undisturbed, that is, it remains quiescent during polymerization whereby the mixture initially forms a continuous gel which ultimately converts to high polymer. If the mixture is disturbed or agitated during polymerization, the resultant polymer has diminished strength, toughness and infrangibility.

The cryotachensic polymerization process generally involves preparing a homogeneous mixture of the monomers and polymerization initiator and copolymerizing the monomers simultaneously by cooling. It is to be understood however that the process also includes partial polymerization of chloral alone, followed by reaction with the other comonomers. In this variation of the process a uniform mixture of only chloral and polymerization initiator, with or without aprotic solvents, is prepared at a temperature above the threshold polymerization temperature of the mixure. The mixture is then cooled below its threshold polymerization temperature under quiescent conditions to partially polymerize the chloral to polychloral. The other comonomer or comonomers are then added to the reaction vessel and caused to copolymerize with chloral under conditions which may be quiescent or not. It is believed the added material copolymerizes not only with the remaining free chloral but also forms block copolymers with the polychloral.

The initiator is always uniformly distributed in the monomer mixture before any polymerization occurs. Thus, when polymerization is brought about by cooling the composition below the threshold polymerization temperature, the composition generally becomes gelled and unflowable within one minute or less. The degree of conversion of monomers to copolymer increases with time but generally is substantially complete within one hour. The order of addition may be varied but in general the initiator is preferably added after the addition of solvent, if any is used; or the initiator may be added in solution.

The threshold polymerization temperature of a polymerization mixture containing monomeric chloral, one or more ketenes and/or one or more isocyanates, isothiocyanates, diisocyanates or diisothiocyanates and an initiator, and optionally a solvent, is determined as follows: The mixture is prepared and thoroughly blended at an elevated temperature, for example, at its reflux temperature or at 65 C., whichever is lower. The mixture is then stirred and cooled at a rate of 2 C./min., the stirring being conducted to insure uniform cooling of the entire mass of liquid. The threshold polymerization temperature is that temperature at which there is noted the first haziness or opalescence due to solid copolymer separating in the mixture.

The monomer initiator solvent compositions have threshold polymerization temperatures in the range from 0-60 C. The threshold temperature is affected by both the nature and the amount of the ketene, isocyanate, isothiocyanate, diisocyanate or diiso-thiocyanate comonomers and any aprotic liquid and its amount present. The maximum temperature at which the polymerization mixture is prepared is not critical and generally falls between the threshold polymerization temperature of the particular mixture and the reflux temperature thereof. Generally speaking, the threshold polymerization temperature is highest with monomers per se while reaction mixtures containing solvents show lower threshold polymerization temperatures. Mixtures containing about 25% chloral by volume have threshold polymerization temperatures near room temperature.

Copolymerization of the monomers in the polymerization mixture can be conducted at the threshold polymerization temperature. However, the heat of polymerization is most readily dissipated and the toughness and molecular weight of the polymer are increased if a polymerization temperature of at least 5 C. below the threshold polymerization temperature is used, and preferably the temperature is at least 25 C. below and still more preferably, at least 50 to 135 C. below the threshold polymerization temperature. Cooling to the desired low temperature may be accomplished by any means known to the art.

The cryotachensic polymerization process can be car ried out in the presence of air. However, it is preferred to use an atmosphere to which the monomers and the initiator are inert. Thus, it is desirable to exclude moisture, oxygen, carbon dioxide, acidic or basic vapors, and vapors of protic solvents. An inert atmosphere is preferred when pure monomers are to be held for substantial lengths of time prior to polymerization and is particularly advantageous when it is desired to hold a mixture containing the monomers and a polymerization initiator above the threshold polymerization temperature of the composition for more than a few minutes. An inert atmosphere may be obtained by operating at reduced pressures, by operating in nitrogen, helium, or the like, or by other means known in the art.

It is preferable to bring about polymerization by cooling the polymerization mixture below its threshold temperature within a short time after contact of the initiator with the monomers. For example, it is preferable to carry out polymerization within one hour after contact of monomers with the catalyst and more preferably within ten minutes or less.

Polymerization initiators suitable for use in the present process are essentially those of my previously mentioned coassigned applications Ser. Nos. 580,217, 558,631 and 731,622, and include all of those known to initiate anionic polymerization. Effective initiating amounts of initiator are generally between 0.001 and of the combined weight of chloral and comonomer(s); preferred amounts are 0.005 to 5% by weight. Many of the initiators are Lewis bases. Examples of initiators include: (a) tertiary organic compounds of elements of Group V-A of the Periodic Table, i.e., compounds QR where Q is N, P, As, Sb, or Bi, and R is a hydrocarbyl group containing 1-18 carbon atoms with the proviso that when Q is N, no more than one R can be aryl. The R groups may be alike or different and can be taken together to indicate the hydrocarbon part of a cyclic 5- to 7-membered ring system in which Q is a heteroatom as in pyridine, substituted pyridines such as trimethylpyridine, quinoline, triethylenediamine, and alkyl, aryl and benzo derivatives of such compounds. Thus the hydrocarbyl groups may be alkyl as in methyl, ethyl, dodecyl and octadecyl, alkenyl as in 9-octadecenyl, aryl as in phenyl, naphthyl, anthryl and benzanthryl, cycloalkyl as in cyclopropyl, cyclopentyl, cyclohexyl and cycloheptyl, aralkyl as in benzyl and phenethyl, alkaryl as in tolyl and xylyl; and the like; (b) onium, particularly ammonium, phosphonium and sulfonium fluorides, chlorides, bromides, iodides, hydroxides, alkoxides, thialkoxides, carboxylates, cyanamides, cyanates, thiocyanates and azides. The onium cations may be hydrocarbyl substituted, the hydrocarbyl groups being as described for the first group of initiators; (c) Group I-A, Group II-A, or Group III-A metal hydrides, hydroxides, halides, alkyls, alkoxides, carboxylates, cyanamides, cyanates, thiocyanates, and azides, and particularly lithium chloride and similar halides; and (d) phosphine and phosphonium compounds wherein the phosphorous atom carries one or more substituents such as: hydrocarbyl groups (as described under (a) above for the first group of initiators); hydrocarbyl groups containing halogen; and hydrocarbyl groups and halogenated hydrocarbyl groups connected to P through oxygen or sulfur. The Periodic Table referred to herein is that set forth in Demings, General Chemistry, John Wiley and Sons, Inc., New York, 5th ed., 1944, chap. 11.

The aprotic solvents, when used as reaction media, must be unreactive with the monomers and the initiator and preferably should be good solvents for each. The resulting polymerization mixture must be homogeneous at the threshold polymerization temperature. Aromatic and aliphatic hydrocarbons, as well as ethers, nitriles and ketones, are preferred. Toluene is particularly preferred. Halocarbons such as carbon tetrachloride, esters and amines such as N,N-dimethylformamide and N,N-dimethylacetamide are operable if the polymerization is carried out within less than one hour and particularly less than a few minutes after mixing of the monomers with the solvent and initiator. Specific solvents suitable for use in the polymerization according to this invention include benzene, n-hexane, cyclohexane, diethyl ether, anisole, acetone, cyclohexanone, methyl ethyl ketone, ethyl acetate, acetonitrile, nitrobenzene, methylene chloride, chloroform, tert-butyl chloride, dimethyl sulfoxide, tetramethylurea, hexamethylphosphoramide and the like. Amounts of aprotic liquid up to 10% by weight aid in solubilizing the initiator in the monomers. High concentrations of aprotic liquid can assist in the application of the unpolymerized mixture as a paint, or for dipping, impregnating and coating operations prior to cooling to bring about polymerization.

With initiators which are readily soluble in the warm monomer mixture, no added liquid is required for dispersing purposes. A small amount of such liquid, however, may be desirable to permit shrinkage of the bulk copolymer by evaporation of the liquid after polymerization. This is sometimes useful in providing for removal of complicated solid shapes from the molds in which they are prepared.

The polymerization mixture can be prepared in the mold in which the polymer is to be formed or the mixture can be prepared in another container and then transferred to the mold which is at a temperature above the threshold polymerization temperature and which is then cooled therebelow to bring about polymerization.

The compositions are useful either as unfilled compositions or filled compositions containing up to about 70% by weight of a filler or reinforcing agent. All filler types known in the polymer art, whether inorganic or organic, may be used. Included are pigments; glass in the form of flakes, fibers, filaments, fabrics, roving, mat, powder, hollow fibers, glass balloons and the like; carbon in the form of carbon black, fibers and graphite; silicas such as diatomaceous earth, fibrous quartz, pulverized quartz, ground silica and pyrogenic silica; boron and metals in the form of a powder, wool or fiber including iron, steel, aluminum, bronze, copper, lead, silver, gold and the like; metal oxides such as iron oxide, alumina, titania, alumina fibers or whiskers, sapphire whiskers, titania whiskers, and the like; salts such as calcium silicate, talc, clays, mica, calcium carbonate, barium ferrite, barium sulphate, boehmite, vermiculite, molybdenum disulfide, asbestos, fibrous barium sulfate, calcite, and the like; dyes; fibers derived from natural or synthetic sources including wool, nylon, polyacrylonitrile, polyethylene terephthalate, polypropylene, polypivalolactone and fluorocarbon plastics such as powder and fibers of polytetrafluoroethylene, polychlorotrifluoroethylene and the like; all as well known in the art.

One or more fillers may be mixed with the monomers, prior to or subsequent to the addition of the polymerization initiator, at a temperature above the threshold polymerization temperature of the mixture. The uniform mixture is then cooled below the threshold polymerization as described above.

The products of the invention are resistant to fire and high temperatures and this property makes them especially valuable in applications where resistance to high temperatures is desirable. The products may be used in their filled or unfilled state and because they are machinable, they may be made into a wide variety of durable, heat resistant shaped solids of all sorts such as chess men, dishes, cups, saucers bowls, balls, dolls and toys of all sorts. They can be made as heat and fire resistant: roofing tiles; architectural sheets and panels one inch or more in thickness; house drain gutters; heater housings; motor coil insulation; structural or resilient foams; fibers for fire resistant cloth, clothing, drapes, rugs and carpets, etc.; fibrids for making heat resistant paper; tough films for packaging and wrapping; potting resins for embedding objects of all kinds; etc., etc.

By employing equipment capable of moving the homogeneous polymerizable mixture of monomers and initiator from a temperature zone above its threshold polymerization temperature through a cooling, polymerization zone to a polymer discharge area, it is possible to carry out the polymerization process on a continuous basis without agitating the polymerization mixture. Continuous polymerization in this manner is suitable for preparing films, sheeting, beading, rods, tubes, pipes and similar shaped objects commonly prepared from other polymers by melt extrusion. Belt casting of transparent sheeting and films is particularly well adapted to this mode of operation.

The internal physical make-up of the shaped chloral copolymers prepared according to this invention is such as to permit ready removal of any solvent or unpolymerized monomers by evaporation, extraction or other common means. This same make-up permits ready access to the interior of large moldings by gaseous reagents or solutions of agents for post-treatment or stabilization, or by solvents for removing initiator residues. Post-treatments of the copolymers with benzoyl chloride, acetic anhydride, and phosphorus pentachloride can be performed.

EMBODIMENTS OF THE INVENTION The following non-limiting examples further illustrate the invention. Parts and percentages are by weight unless otherwise noted.

EXAMPLE 1 Copolymer of chloral and phenyl isocyanate A mixture of 160 ml. of chloral and 160 ml. of toluene was added to a 1 liter round-bottom flask equipped with a nitrogen inlet and outlet, a reflux condenser, a mechanical stirrer and a thermometer. To this mixture, which was at a temperature of 25 0., there was added with rapid stirring a solution of 0.30 g. of lithium tert-butoxide in 480 ml. of dried toluene. The stirring was discontinued after the mixture had become completely homogeneous and it was determined that its threshold polymerization temperature was 22 C. When the mixture became quies cent, that is, was no longer in an agitated state, the flask containing the quiescent mixture was cooled down to and held at -78 C. for 16 hours while maintaining the mixture in its quiescent state. At the end of the 16 hours some of the chloral had homopolymerized to a solid gel. The flask was then connected to an oil pump and held under reduced pressure for a period of 24 hours to remove most of the solvent. During this time the flask and its contents were allowed to warm up to room temperature. 50 ml. of phenylisocyanate was added to the flask containing the coalesced mixture of chloral monomer and chloral homopolymer and allowed to react for 16 hours. After that time excess phenyl isocyanate was drained off and the flask broken. The polymer was washed with toluene, and dried. 155 g. of copolymer was obtained in spherical form reflecting the shape of the container in which it was made. Characterization of this polymer by nitrogen analysis (Found: N, 0.89%, 0.99%) showed that 10 mole percent of phenyl isocyanate had copolymerized. The polymer was tough and insoluble in common organic solvents.

EXAMPLE 2 Copolymer of chloral and phenyl isocyanate In a procedure similar to that of Example 1, a mixture of 200 ml. of chloral and 600 ml. of toluene containing 0.27 g. of lithium tert-butoxide (threshold polymerization temperature 30 C.) was prepared at a temperature above 30 C. The quiescent, homogeneous mixture was cooled down to and held at '78 C. for 16 hours. To the resulting gel mixture of polychloral and chloral monomer (approximately 30% of the monomer initially charged) was added 100 ml. of a 20% (by volume) solution of phenyl isocyanate in toluene. After 8 hours, solvent and excess phenyl isocyanate were removed under reduced pressure and the product was washed in toluene and dried to obtain 237.5 g. of polymer containing 8 mol percent of copolymerized phenyl isocyanate. This copolymer was also tough and insoluble in common organic solvents.

EMMPLE 3 Copolymer of chloral and phenyl isocyanate Part A: In a dry test tube (18 x 200 mm.), which was blanketed with nitrogen, a mixture of 30 g. of freshly distilled chloral and 2.7 g. of freshly distilled phenyl isocyanate was heated in an oil bath to 65 C. A 1 molar solution of lithium tert-butoxide (0.4 ml.) in cyclohexane was then added. The threshold polymerization temperature of this mixture was 47 C. One part of the initiated mixture was left in the test tube until the mixture became quiescent and the tube was then placed without shaking into a --50 C. bath. Polymerization commenced almost immediately. The polymerization was essentially complete in one hour. The tube containing the copolymer was taken out of the cooling bath and allowed to come to room temperature. The plug of chloral-phenyl isocyanate copolymer was removed from the test tube and washed with carbon tetrachloride. Elemental analysis for C, H, and N (see Table I) indicated that the polymer contained 10 mole percent of phenyl isocyanate. The infrared spectrum showed a strong band at 5.70;. indicative of a urethane linkage.

Part B: The other part of the initiated comonomer mixture was drawn into a warm syringe and placed between glass plates, separated by a 0.1 mm. gasket, at a temperature above 65 C. and allowed to become quiescent. The quiescent mixture was polymerized by cooling the assembly at 50 C. for one hour. The resulting film was washed with carbon tetrachloride. A clear film of chloral-phenyl isocyanate copolymer was obtained which was stiff and tough. The polymer was insoluble in common organic solvents. The thermal stability of this sample was substantially improved over the homopolymer of chloral. The 5% weight-loss temperature of the copolymer determined at a heating rate of 6 C./min. in nitrogen was 197 C. and 200 C. in two samples; typical samples of chloral homopolymer had a 5% weight-loss temperature in the range of -120" C.

EXAMPLES 4-40 Similar copolymerizations of chloral were carried out with other isocyanates as comonomers. The procedures of Example 3, Parts A and B, were followed exactly and the results are shown in Table I which follows. In the table the modulus values refer to stiflness or tension.

Copolymer Film r erties, Part B Comonomer Mole analysis (percent) Mole p p percent percent Tensile Elongation Chloral Amount chloral chloral strength at break Modulus Example (1111.) Type (ml.) in feed 0 H N inpolymer (p.s.i.) (percent) (p.s.i.)

20 Phenylisocyanate 3 as 20.55 1.11 90 5,720 8.8 20 Methylisocyanete.-. 3 80 20 n-Butylisoeyanate 3 88.5 17.00 1.05 95 5,400 223 173,000

20 Oetadecyliso0yanate...-;-; 7 90 22.20 2.07 94 0,220 6.8

7-.-; 20 Dodecylisooyanate 90 19.50 1.07 95 6,880 208 225,000

9 20 Isopropylisocyanate a 80 16.81 0.75 97 5,900 70.9

0 20 Toluene 0115001 90905- 3 90 21.27 1.24 89 5,490 9 a 171,000

10 20 l-naphthylisocyanate a 90.5 15.95 1.20 95 5,950 29 a 149,000

1 20 Ethylisocyanate a 04 17.05 0.95 91 5,700 0.0

12 10 n-Butylisocyanate 2.85 so 18.74 1.12 91 7,120 12.9 300,000 19 20 .15 2.25 91 17.15 0.91 {3 2? 95 5,070 10.0 221,000 14 20 .do 1.15 95 17.07 0.89 95 7,400 15 5 115,000 15 715 0.57 97.5 10.77 1.00 {3'2 97.5 5,000 9 3 254,000

20 0,0,0.,a'-Tetramethylxylylene 0 94 15.01 0.86 99.4

diisocyanate. 20 4,4'-diis0cyanatodicyclohexylmethane. 3 94.5 16.32 0.89 97.5

20 Hexamethylene diisocyanate 3 91 18.83 1.24 94 20 Phenyl 150911150 911.0155 2.05 91 15.70 1 24 99.7

20 n-Butylisothi00yanate..;.. 1 0.13 98.7 20 Methylisothiocyanate 1.5 0.19 98.4 20 Methylisoeyanato 1 0.93 91.6 20 2,5-dichlorophenylisocyanate. 2 0.36 96 20 34-d1bromophenyhsocyanate 6.1 0.52 95 20 p-Bromophenyl isocyanate. 3.96 0.89 90 1 20 o-Ohlorophenylisocyanate- 3.07 0.77 91.6 31.8 20 m-Ohlorophenylisoeyanate 3.07 1.00 89 16.3 20 p-Chlorophenylisocyanate. 3.07 1.12 87.5 40.8 20 o-Methoxyphenylisocyanat 2.98 0.94 v 90 17.8 20 p-Methoxyphenyllsocyanat 2.98 1.03 89 20.3 20 o-Ethoxyphenyl1s00yanate-.. 3.26 0.93 90 17.3 20 p-Ethoxyphenylisocyanate 3.26 1.01 89 17.8 20 o-Nitrophenylisocyanate- 3.24 0.93 95 28.8 20 m-Nitrophenylisoeyanate 1.39 93 5.5 20 p-Nitrophenylisocyanate" 1.42 93 4.0 20 o-Tolylisocyanate 12.66 1.28 87.5 25.0 20 m-Tolyl isocyanate-. 2.66 0.62 94 20.6 20 fiTolyl isoeyanate 2.60 0.62 94 28.8 20 ethylene (ii-phenyl diisocyanata. 3.3 4.5 20 Oetylisocyanate 3.0 92 0.12 98.7 5,910 50.0

1 Grams. 3 Saturated solution.

EXAMPLE 41 Copolymer of chloral and phenyl isocyanate In a dried test tube, 4 ml. of chloral and 0.4 ml. of phenyl isocyanate were dissolved in 20 ml. of toluene. The resultant mixture was heated to C. and 0.12 ml. of l-molar lithium tert-butoxide in toluene Was added thereto. The test tube was stoppered and the quiescent mixture was cooled to 20 C. The mixture set up in a few minutes to a transparent gel. After one hour, the tube was allowed to come to room temperature and to stand overnight. Toluene was partially removed under reduced pressure and the polymer plug was taken out of the test tube. The polymer gel had collapsed and was clear. Toluene and traces of unreacted monomers remaining in the polymer were allowed to evaporate at room temperature in the air. A coherent plug of chloral/phenyl isocyanate copolymer was obtained having the characteristic IR absorption of 5 .70 1.

EXAMPLE 42 Copolymer of chloral and phenyl isocyanate then placed without shaking in a bath at 20 C. After a few minutes, the contents polymerized to an opaque mass. After one hour the test tube was allowed to come to room temperature. The test tube was opened and some pentane was allowed to evaporate until the polymer shrank from the glass surface. The polymer was removed from the test tube and pentane and unreacted monomers allowed to evaporate completely (one day). The polymer mass weighed 7.2 g. and had the shape and approximate volume of the test tube. The polymer was cut in half and the cut faces showed the physical structure of a foam of very fine pore size. The density of this foam was 0.35 (as compared to polychloral of 1.9). The infrared spectrum determined on a thin section of the foam showed the characteristic bands of a chloral-phenyl isocyanate copolymer especially the strong urethane band at 5.70

The following example illustrates the variation in characteristics produced by varying the proportions of the reactants.

EXAMPLE 43 Copolymer of chloral and phenyl isocyanate A series of test tubes were charged under nitrogen with chloral and phenyl isocyanate in the amounts indicated below and heated to 60 C. To each tube was then added 0.8 ml. of a one molar solution in chloroform of a polymerization initiator, 1/1 triisopropyl phosphine/ chloral salt having the formula 1 1 to form a homogeneous mixture (see Example 105-C below for preparation of this initiator). After each mixture had become placid it was cooled without agitation to C. and held at that temperature for 16 hours. The data below give the properties of the resultant copolymers.

Charged CGHSNCO) Nature of resultant Isolated Ex. Chloral, Mol material containing copolymer, 43 m1. Ml. percent the copolymer grams 11.8 8.7 Solid 15.9 9.8 11.0 ---do- 14.7 7.9 13.2 do 12.5 5.9 15.4 70 Visa, clear 8.8 5.9 15.4 70 Very visc., e1ear.---. 9.1 4.9 16.5 75 Visc.,elear 7.6 5. 9 17. 6 80 SI. v1sc., clear 5. 5

Copolymers A, B, and C were ground in methanol in a high speed blender. The particles were then washed thoroughly with methanol, then with acetone, and then dried. Materials D, E, F, and G were dissolved in benzene and then precipitated into a large volume of methanol. The resultant particles were washed with methanol, then with acetone, and finally dried.

The isolated polymers showed the following properties:

yl isocyanate, 13 m1. of 2,4-diisocyanatotoluene, and 0.25 g. of Celanthrene red dye. The flask was equipped with a stand pipe which was closed with a calcium chloride tube. The mixture was heated to C. and 15 ml. of a 1- molar lithium tert-butoxide solution in cyclohexane was added to form a uniform mixture. The threshold polymerization temperature of this mixture was determined to be 47 C. After the mixture became quiescent, the flask and its contents were placed without agitation in a bath at 78 C. and polymerization commenced immediately. After 16 hours, the flask was brought to room temperature. The contents had polymerized completely to a brightred, almost transparent sphere of chloral/butyl isocyanate/phenyl isocyanate/2,4 diisocyanatotoluene copolymer. The block was hard and tough, and had the exact shape of the vessel in which it was prepared.

Other examples of the copolymers of this invention are obtained when the following isocyanates, diisocyanates, isothiocyanates and diisothiocyanates are used in place of phenyl isocyanate, as for instance in the procedure of EX- ample 3:

methoxydifluoromethyl isocyanate; 2 (4-ethylphenyl) 1,1-dimethylethyl isocyanate; Z-benzo [b] thien-3-yl-1-methylethyl isocyanate;

Inherent viscosity,

801. in C. benzene -or1-o- 601.

units derived from chloral and units derived from phenyl isocyanate.

EXAMPLE 44 Copolymer of chloral, butyl isocyanate, phenyl isocyanate and 2,4-diisocyanatotoluene In a 300 ml., round-bottom, glass flask were placed 250 ml. of chloral, 13 ml. of butyl isocyanate, 13 ml. of phen- 1,5-naphthylene diisocyanate;

p[bis-(2-chloroethyl)amino]phenyl isocyanate;

ethoxycarbonylmethyl isocyanate;

3-cyano-l-methyl-3,3-diphenylpropyl isocyanate;

o-cyanophenyl isocyanate;

l-diethylamino-1,2,2-trifluoroethyl isocyanate;

a,a-dimethylphenethyl isocyanate;

heptafluoropropyl isocyanate;

2-iodo-1-indanyl isocyanate;

4-phenylanhtry1 isocyanate;

2,6-anthraquinonylene diisocyanate;

3-benzyloxy-4-methoxyphenethyl isocyanate;

trifluoromethyl isocyanate;

1,2,3,4,4a,9,10,10a-octahydro-7-isopropyl-1,4a-dimethyll-phenanthryl isocyanate;

2,4,6-triiodophenyl isocyanate;

abietyl isocaynate;

6-fluoro-2-pyridyl isocyanate;

l-adamantyl isocyanate;

3,3,3-trinitropropyl isocyanate;

2-(phenylthio)ethyl isocyanate;

p-phenylazophenyl isocyanate;

benzyl isothiocyanate;

butyl isocyanatoacetate;

p-bromophenyl isothiocyanate;

p-butoxyphenyl isothiocyanate;

o-chloro-a-phenylbenzyl isothiocyanate;

14-cyanotetradecyl isothiocyanate;

cyclohexyl isothiocyanate;

cyclooctyl isothiocyanate;

2-diethylaminoethyl isothiocyanate;

2,2-difluoroethyl isothiocyanate;

2,4-dinitrophenyl isothiocyanate;

ethylene diisothiocyanate;

p-iodophenyl isothiocyanate; 4-methylthiobutyl isothiocyanate; p-phenylene diisothiocyanate;

Z-pyridyl isothiocyanate; p-(methylthio)phenyl isothiocyanate; and 9-phenanthryl isothiocyanate.

EXAMPLE 4s Copolymer of chloral and diphenyl ketene 14 chloral homopolymer prepared by a similar process had weight loss temperatures in the range of 85-120" C.

EXAMPLE 46 Copolymer of chloral and butylethylketene A copolymerization was carried out by the procedure of Example 45 using butylethylketene as the comonomer. Components: 20 ml. of chloral, butylethylketene ml. of a solution in hexane), and lithium tert-butoxide (0.4 ml. of 1 molar cyclohexane solution). The film was clear, tough, and insoluble. The infrared spectrum of this copolymer showed a strong absorption band at 5.75,u indicative of an ester linkage. The 5% weight loss temperature was 153 C.

EXAMPLES 47 AND 48 Copolymerizations of chloral were carried out with dimethylketene and pentamethyleneketene using the procedure of Example 45 to produce films. These are tabulated in Table 11 together with Examples 45 and 46.

TABLE II.COPOLYMERIZATION OF CHLORAL WITH KETENES Mechanical properties of films Molar Copolymer Mol teed analysis percent Comonomer ratio Initl- (percent) chloral Tensile Ultimate Chloral chloral! ator 1 in strength elongation, Ex. Type Amount, g. ketene (ml.) 0 H copolymer (p.s.i.) percent 45 1s Diphenylketene 1 2o 0. 2 {g 8- 96. 7 6,330 20. 5 46 Butylethylkatene 2 12.6 0.4 16.82 0.82 47 30 Dimethylketene 1. 2 12 0. 4 17. 23 1. 14 48 30 Pentamethyleneketena-.- 0. 8 28 0.4 17. 17 1. 04

1 Lithium tert-butoxide (1 molar) in cyclohexane.

the tube was placed without agitation into a C. bath. 50 EXAMPLE 49- Polymerization in the unagitated mixture commenced almost immediately and was essentially complete in 1 hour. The tube containing the copolymer was taken out of the cooling bath and allowed to come to room temperature. The plug of chloral-diphenylketene copolymer was removed from the test tube.

Part B: The other part of the initiated comonomer mixture was transferred under nitrogen at temperatures above 65 C. to a mold formed by two glass plates separated by a strand of elastic fiber about 0.1 mm. thick. The assembly with its unagitated contents still under nitrogen was then placed in a bath at -40 C. and maintained in placid condition for about one hour. A clear film of chloral-diphenylketene copolymer was obtained which was stiff and tough. The film was washed with carbon tetrachloride and dried. The polymer was insoluble in all common organic solvents. Elemental analysis for C and H (Table II) indicated that the polymer contained 3.3 mole percent of diphenylketene. The infrared spectrum showed a strong band at 5.75, indicative of an ester linkage. The thermal stability of this sample was substantially improved over chloral homopolymer. The 5% Weight loss temperature of the copolymer determined at a heating rate of 6 C./min. in nitrogen was 235 C. Typical samples of Copolymer of chloral and dimethylketene In a 50 ml. glass polymerization tube was placed a sealed vial containing 0.2 ml. of a 2 molar solution of lithium tert-butoxide in cyclohexane and several steel balls. Chloral (30 g.) was added to the tube and dimethylketene (1.2 g.) was then condensed into the tube. The supernatant air in the tube was evacuated after which the tube was sealed and heated to 60 C. The tube was shaken vigorously to cause the steel balls to break the vial containing the initiator and to produce a homogeneous solution. After the contents of the tube had come to rest it was placed without agitation in a -30 C. bath. Polymerization commenced in the placid mixture almost immediately. The tube was taken out after an hour and the polymerization was allowed to go to completion overnight at room temperature. The initial yellow color of the solution almost completely disappeared during the polymerization. The tube was opened and a tough and stiff chloral-dimethylketene copolymer was obtained. Elemental analysis for carbon and hydrogen indicated the polymer contained 6% of dimethylketene, and the infrared spectrum of the polymer showed a strong ester band at 5.75;.

EXAMPLES so AND 51 gas present to minimize the formation of voids in the final product.

Rigid shaped objects can be produced with the catalyzed filler-monomer mixture such as flat, curved, cor- IABLE IIL-OOPOLYMERIZATION 0F OHLO RAL WITH KETENES Molar Copolymer feed analysis Comouomer ratio Inipercent Mol percent Chloral chloral] tiator chloral in Ex. (g.) Type Amount, g. ketene (ml) 0 H copolymer 49 30 Dimothylketene 1.2 12 0.4 i: 98.0 50 30 Ketene 1.0 8.5 0.4 16.95 0.88 95.2 51 so Methylketene 1.2 9.5 0.4{ 96.1

1 Lithium tert-butoxide (1 molar) in cyclohexane.

When the following ketenes are substituted for dimethylketene in the procedure of Example 49, the corresponding chloral-ketene copolymers are obtained:

phenoxyketene;

p-chlorophenoxyketene; 2,4-dichlorophenoxyketene; 2,4,6-trichlorophenoxyketene; diphenoxyketene; bis(p-biphenylyl)ketene; di-p-tolylketene;

dimesitylketene;

dodecylethylketene;

durylphenylketene;

tetradecylketene;

octadecylketene;

benzylmethylketene;

cyclohexylketene;

dimethyleneketene (carbonylcyclopropane); tetramethyleneketene (car-bonylcyclopentane); l-naphthyl phenylketene; 3,3,3-trichloropropylketene; p-methoxyphenylketene;

dicyanoketene (carbonylmalononitrile); (ethoxycarbonyDketene; and (ethoxycarb onyl) -p-tolylketene.

FILLED COMPOSITIONS It has been pointed out above that the copolymers of this invention can be combined with fillers and reinforcing of all types whether inorganic or organic.

The chloral copolymer moiety of the filled compositions forms a matrix representing 1-99% by weight, of the total weight of the filled compositions and preferably 60-95% of the total weight of the filled compositions. When fiber fillers are used, such as especially treated glass fibers capable of chemical bond formation between the copolymer and glass fiber, tough rigid reinforced objects can be obtained. The filled chloral copolymer compositions, in general, possess a combination of mechanical and physical properties as follows: good weathering, high rigidity, non-burning, as they do not support combustion, and good tensile and impact strength. When a bond is formed between the matrix resin and the filler, an added property of good hydrolytic stability is obtained. Preferably, this bond should be a chemical bond such as that formed between the copolymer and glass treated with a vinyl-silane or Werner-type chromate complex containing an addition polymerizable group. However, good properties are observed in filled compositions where the bond between the matrix copolymer and filler is other than a chemical bond such as a Van der Waals bond.

Filled compositions are prepared by mixing fillers with a catalyzed mixture of chloral and comonomers prior to cryotachensic polymerization. Alternatively, the filler can be mixed with the mixture of monomers, then after complete mixing, the desired quantity of initiator is added to the mixture, prior to cryotachensic polymerization. It is preferable to degas the catalyzed mixtures prior to polymerization to remove oxygen and any other dissolved rugated or otherwise shaped sheets for glazing and architectural uses, automobile bodies, exterior step treads, boat hulls and decking, fishing poles, fire barriers, laundry tubes, electrical appliance housings, bearings, motor insulation, rocket motor casings and the like. The non-burning characteristics of the products of this invention make them particularly advantageous in these uses.

The mechanical properties of the reinforced copolymer panels compare very favorably with the mechanical properties of available fiber glass reinforced polyester compositions.

The chloral copolymer reinforced sheets are completely noncombustible whereas polyester panels burn vigorously and even so called flame retardant compositions support combustion when compared in the American Society for Testing and Materials (ASTM) flammability test D635- 63.

EXAMPLE 52 Copolymer of chloral and p-phenyl isocyanate filled with glass wool A layer of glass wool about 3 mm. thick, measuring about 220 mm. x mm. and weighing about 15 g. was placed between two 3 mm. glass plates measuring mm. x 280 mm. A length of 6 mm. x 1.5 mm. wall gum rubber tubing was inserted between the plates about 1" in from the edges to serve as a gasket which was liquid tight except for a small opening near one corner through which the polymerizable monomer mixture can be introduced. The assembly was clamped together with spring clamps on all edges and heated to 60 C. A mixture of chloral (93.5 ml.) and p-chlorophenyl isocyanate (6.2 ml.) was heated under nitrogen to 68 C. and mixed with 4.0 ml. of a 1 molar solution of triphenyl phosphine in benzene. This initiated monomer mixture was transferred with a preheated (60 C.) hypodermic syringe havin a large bore (12 ga.) needle long enough to reach nearly to the bottom of the glass-filled mold. The preheated mold was carefully filled, from the bottom up in order to displace the air trapped in the glass, with the hot mixture of initiated monomer. With the polymerization mixture in quiescent condition, the filled mold was quickly immersed in ice water taking care to keep any water from getting into the casting through the opening in the gasket and to keep the polymerization mixture quiescent during the polymerization. After one hour the mold was removed from the ice bath and allowed to warm to room temperature overnight. One half (A) of the strong, hard, nearly transparent reinforced chloral/p-chlorophenyl isocyanate copolymer sheet was cured in a 100 C. air over. After 24 hours it had lost 22.2% in weight, but was essentially unchanged in length or width. The other half (B) of the sheet was allowed to air dry. It lost less than 3% in weight in one week.

Examples 53-80 which follow, show the preparation of chloral homopolymer and copolymer sheets reinforced with selected fibrous materials and prepared in the manner indicated. The detailed procedure of Example 52 was used except for the differences shown.

0808820800 0008000000 380 8082 00 0.88 00800 08802 Amy 0.600 08 8 00 0080 00 8 50082 0 0 00 00008 8 0008 00 mm 0388mm 00 080 8 0 80008380 8 0008 000 000 080 808030820.80 0 0 0 80 8 00 050 0.80 808 30800 00800 0 00 00080 0008008008 @80 0 8.8 8% 00008 -08 0803 0803808808 080 08000002038308 00 0 00 8303808 080 000 .80 00000 8000 0053 0803 000080 0. 200 8263 020 000% .8000 80 0 00080 08 0830 00 .88 0N 0 OH .88 M: .0800 :N 0 0 008030808 0880 080 0 00 8008030 00000 08 00500 00 0 080 0 0 02000 00 080 80 0.5 0003 00080 00 0 0 0800808800 8008 00 008803 00 000580000 0 8002 008808 88 800000808200 0 0 080.0080 080 03 080 00 00 8 0m 808 8 088 080 00 0000800 .80 0 0 00 0: 0 80 0 0003 000580000 00:0 0 0 080 20008 080000 0008000000 80 808030 0d a080 00 h80 Q0000080 00m 8dHm 0000808000 0 080E 008080 H "000808000000 080300 00 $00 600880000000 0805 0 0 wgwflm 08000 $80 E H "0000805000 380 mH 0008000000 0808000Nfl0 008000800 8 0 800 3880 3 E QE "0008080000 E80 8080 08 8a0Z 000 0080 0830mm m 00 08050 08000002038208 80 00880.5 80 00 808 08080 0 0 00 0 0080800 08.80 800 00 00m 8 0008080000 380 8080308 0800808 0008 2 0 NH I 40 00 08 0008080000 380 832 08 08800808 0 08 NH 0 0 0 08 02 0008000000 080 882 08 0800808 0008 m m 3 l 400; 5" 000800000 380 8080308 0800 08 0008 0 m 0 JSAH 03 0008080000 380 8080308 0800008 0008 m 0 0 40 08 0008000000 380 880308 08800808 0008 H 0 3 .1 404. SA 000808000000 080800 0800808 0008 0 H 2 .80 80 008 00080800050 080 00 0800.08 0008 m 0 0 a: 03 4080 00 08 00000 08 0 000 0 08 0 085m 0 0 I- -0802 00% 808020800 000808008 R80 8000 0000N 082 0 0008 08 00 000 0 cfimflmmflmo w m 2 H80 00H 00 0 00 080 008380 80000080 00m 0 Qd 080 0 00080 08 00 000 0 00 0 085m w 0 030 3 03 8088000800 00080800000 0803 008080800.82 0 000800 08 00 000 0 00 08 08085 0 3 wodfi 03 00080800000 080 00 0800808 0008 n 0808020800 000808000 0 080800308030 00080 000 00 000 0 00 0 wno m m5 rmndfi 000 80830800 08000 080 8 8008030 0008 08 00 000 0 0.8 0 0885 m 3 i 0008 0 3 8088030800 000808000 0 880 3 08020 00080 08 00 000 0 080 08085 N 0 900 0 03 002 080808 00 00 0 0 40 0 m 03 0030 0800808 0 0 00 m 2 40 0 0 03 0020 0800808 40 0 3 0 0 40 0 m 03 00 0800.08 80 0 08 0 N. 0 m 0 3 0020 0800.808 0 0 0 0 0 40 0 0 03 00000 00820800 000800 08 0.808 080.8% 5 {00.--} m0 0 i. 400 0 03 8088008800 0 00 83x2 28 0 88 .8 0 8 0 8 N. 2 0 000 mm 2.808 8 0 0008 m0 0 00 2 m 08 08 08 0 0 000 8 8 88 0 088 0% m8 .MEMmwfl. 0 80 0 80 0. 0 00 3 5i: 1::- o I Q 0 08 0 0 000 08 IiZl-PG 80 m0 0 4m 0 0 m0 6Q 00 .0 I :0 2 m0 0 88 0 0 00 0 8 i! B m 8 0 8 88 0 0 0 8 0 0 0 000 0 0 8 4 80 0 000 0 00 0 0 030 8 8 00 6Q 00.0 E 0 a H .i... I. E.. 000 0 8088000800 0008 08 00 0 @8005 mm m h 000 0 m0 0 0d 0 0 m0 2 080000-00.M 08E0m 0m 0 00 m .800 an mm 80830800 00080000000 3 8 28 5 3 0 08 0 0 8 0 8 mm H i 000 000 m 000 0 88800 8008 m0 0 I: m 00 m 80 V 0008 00000 n 0 8080m 35 85 00 2 0 8 3 0 8 00800808 2 0 5 080000.88 80000005 8080 0082 0 0 0 80002 80 0080800 008000@ 038002 8 0 0080000 88- 803 80800 000880 03 00805 0080.0 0800.0 800800 08 805E 00 0 02 0 088800 8 0080 0 8080802 its bottom end with a solid rubber stopper. The upper stopper of the outer tube was additionally provided with two smaller holes opening into the bore of the outer tube, one to admit nitrogen gas and the other, itself loosely stoppered, to admit monomer and initiator into the bore of the outer tube. Hot (65 C.) Water was circulated through the smaller tube and a 65 C. water bath raised around the outer one. A mixture of chloral (625 m1.) and phenyl isocyanate (29 ml., 4 mole percent) was heated to 65 C., mixed with 33 ml. of 3.2% lithium tert-butoxide in cyclohexane and used to fill the annular space between the concentric tubes and the resulting homogeneous mixture allowed to become motionless. Circulation of the hot water in the inner tube was continued but the hot water bath surrounding the outer tube was removed. A -20 C. cooling bath was then raised around the outer tube at the rate of 3 mm. per minute until the cooling bath reached the top level of the quiescent polymerization mixture and completely surrounded it. Cooling of the outer tube was continued for 30 minutes while the inner tube was still being kept warm. After 30 minutes of standing under these conditions, the flow of hot water into the inner tube was stopped and the hot water in the tube was removed by suction, the cooling bath still being in position around the outer tube. After another 30 minute period the stopper closing the bottom end of the inner tube was removed thus allowing the -20 C. bath liquid to enter and fill the center tube. After 30 minutes of thus cooling both the inside and outside tubes, the cold bath was removed and the resulting copolymer product allowed to warm to room temperature overnight before the glass was broken away. The resulting pipe section was void-free and had a smooth Outer surface. The inner surface was relatively rough and uneven. Since the manner of cooling caused polymerization to occur from the outer wall inward, the shrinkage which occurred during polymerization caused the polymer to shrink away from the inner tube. The inner surface was machined smooth to give a strong pipe about 200 mm. long, 75 mm. OD, and 50 mm. ID.

EXAMPLE 82 Chloral, p-chlorophenyl isocyanate, diphenylketene terpolymer In a dry 250 ml. glass flask which was continuously blanketed with nitrogen, there was mixed 140 ml. of freshly distilled chloral, 9.3 ml. of p-chlorophenyl isocyanate and 1.5 ml. of diphenylketene. The mixture was heated to 65 C. and 6.0 ml. of a 1 molar solution of triphenylphosphine in benzene was added and mixed in well to form a uniform mixture. The initiator-containing mixture was transferred at temperatures above 60 C. to a mold formed of two glass plates separated by a 3 mm. gum-rubber gasket and the mixture allowed to become motionless. The assembly was cooled at C. to bring about polymerization of the motionless mixture. The mold was opened after polymerization had been completed to release a clear, tough 3 mm. thick sheet of chloral/p-chlorophenyl isocyanate/diphenylketene terpolymer useful for glazing.

EXAMPLE 83 (A) Chloral, p-chlorophenyl isocyanate, dodecyl isocyanate terpolymer The procedure of Example 82 was repeated, using a mixture of 140 ml. chloral, 7 ml. p-chlorophenyl isocyanate, 2 ml. dodecyl isocyanate and 6.0 ml. of a 1 molar solution of triphenylphosphine in benzene. A tough, clear sheet of chloral/p-chlorophenyl isocyanate/dodecyl isocyanate terpolymer was obtained.

(B) Chloral, p-chlorophenyl isocyanate, hexyl isocyanate terpolymer The procedure of Example 82 was repeated using a mixture of 140 1111. Chloral, 7 ml. p-chlorophenyl isocyanate, 2 ml. hexyl isocyanate and 6.0 ml. of 1 molar solution of triphenylphosphine in benzene. A tough, clear sheet of chloral/p-chlorophenyl isocyanate/hexyl isocyanate terpolymer was obtained.

EXAMPLE 84 Chloral, diphenylketene, 3,4-dibromophenyl isocyanate, hexamethylene diisocyanate tetrapolymer Part A: In a dry SOO-ml. Erlenmeyer flask, which was blanketed with nitrogen, a mixture of 210 g. (1.40 moles, 93.6 mole percent) of freshly distilled chloral, 9.2 g. (0.05 mole, 3.1 mole percent) of diphenyl ketene, 8.3 g. (0.03 mole, 2.0 mole percent) of 3,4-dibromophenyl isocyanate and 3.3 g. (0.02 mole, 1.3 mole percent) of hexamethylene diisocyanate was heated to 55 C. A l-molar solution of triphenyl phosphine in benzene (6.0 ml.) was then added and mixed in well to form a homogeneous solution. One part of this heated mixture was transferred into a warm test tube, and the tube was then cooled to 0 C. without agitation. Polymerization commenced almost immediately and was essentially completed in one hour to form a tetrapolymer. The tube containing the tetrapolymer was then allowed to come to room temperature. The plug of chloral/diphenyl ketene/3,4-dibromophenyl isocyanate/hexamethylene diisocyanate tetrapolymer was then removed from the test tube, extracted for 50 hours with acetone, dried for 20 hours at 60 C./1 mm. and analyzed: C, 19.41; H, 1.00; N, 0.27; Br, 2.75; and Cl, 66.66. This corresponds to a chloral/diphenyl ketene/3,4-dibromophenyl isocyanate/hexamethylene diisocyanate molar ratio of 1.5/ 2.5/ 1.0 for which the calculated analysis is C, 18.73; H, 0.83; N, 0.41; Br, 2.60; Cl, 66.67.

Part B: Another part of the above heated initiated mixture of monomers as prepared in Part A was transferred at temperatures above 55 C. to a mold formed by two glass plates separated by a strand of elastic fiber about 0.1 mm. thick. The assembly and its quiescent contents was then cooled to 0 C. without agitation and kept at that temperature for about one hour. A clear film of chloral/diphenyl ketene/3,4-dibromophenyl isocyanate/ hexamethylene diisocyanate tetrapolymer was obtained which was stiff and tough. The composition was the same as the product in Part A above. The infrared spectrum of the film showed a strong band at 5.70 indicative of a urethane linkage and a weaker, well separated band at 5.85 indicative of an ester linkage.

Part C: Another part of the above described, heated initiated mixture of monomers as prepared in Part A was transferred at temperatures above 55 C. to a mold formed by two glass plates separated by rubber tubing to make 3 mm. thick sheets. The assembly and its quiescent contents was then cooled to 0 C. without agitation and kept at that temperature for about one hour. A clear sheet of chloral/diphenyl ketene/3,4-dibromophenyl isocyanate/hexamethylene diisocyanate was obtained which was stiff and tough. It was extracted with acetone as described in Part A. Elemental analysis for C, H, N, and Br (C, 18.99; H, 0.98; N, 0.26; Br 2.29 Cl, 67.21) indicated the chloral polymer contained 95 mole percent of chloral, 1.5 mole percent of diphenyl ketene, 2.5 mole percent of 3,4- dibromophenyl isocyanate, and 1.0 mole percent of hexamethylene diisocyanate. The infrared spectrum (Nujol mull) showed a strong band at 5.70 1. indicative of a urethane linkage, and a weaker, well separated band at 5.85 1. indicative of an ester linkage.

EXAMPLE 85 Chloral-phenyl isocyanate copolymer filled with carbon black An initiated monomer solution was prepared by mixing 30 ml. of chloral, 150 ml. of toluene and 0.12 g. of lithium tert-butoxide at 30 C. To 25 ml. of this solution in a ml. Erlenmeyer flask closed with a rubber stopper was 21 added 0.2 g. of carbon black. The flask was shaken quickly to disperse the carbon black and when uniform and quiescent, the mixture was placed in an ice bath and held there until the chloral monomer gelled. Polymerization was completed by cooling to C. for 12 hours. Residual 22 phthalocyanine blue, beta quinacridone, gamma quinacridone, coated lead chromate pigment (U.S. Pat. 2,885,- 366), coated molybdate orange pigment (U.S. Pat. 2,885,- 366), and nickel azo complex.

The uniform, quiescent mixtures were placed in an ice solvent was removed at 0.2 mm. pressure. The polymer 5 bath for 2 hours and then allowed to stand for 16 hours plug obtained was soaked with a 20% phenylisocyanate at room temperature. The polymerization was accomsolution in toluene for a time suflicient to allow formation plished smoothly and gave polymer pieces which lost apof a copolymer of chloral and phenylisocyanate. The samproximately weight upon heating for 1 hour at 120 ple was washed and dried to give a shiny black block of 10 C. The pieces did not change color during the heat treatpolymer which was machined into a flat chip about 4 mm. ment. thick and 33 mm. in diameter. EXAMPLE 88 EXAMPLE 86 Chloral, p-chlorophenyl isocyanate copolymer (A) Chloral, p-chlorophenyl isocyanate copolymer fined wlth mamum dwxlde with phthalocyanine blue pigment To a mixture of chloral (140 ml.) and p-chlorophenylisocyanate (9.3 ml.), at 50 was added a one molar benexperiment s1mflar.t Examlile 85 W earned out zene solution of triphenylphosphine (6 ml.) and finely with copper phthalocyanme blue pigment instead of cardivided Tioz (4 g This mixture was placed between bon black. Copper phthalocyanine blue (0.025 g.) was dispersed in the above initiated chloral mixture (40 ml.) ifi f ggj fi s ;z g g i fi g aggf gig fik in and polymerization was carried out as described above to an ice bath 1 hourqand then held a 16 glows at give a copolymer plug having a deep blue color room temperature for completion of the polymerization. (B) Chloral, p-chlorophenyl isocyanate copolymer with The pigmented p ym sheet was heat treated for 1 o polytetrafluoroethylene flock as filler 25 at t Weight 1085 Was 19% to 8 8 Whlte,

opaque s ee slmlllar f g j g For each of the following dyed copolymer preparations Y i p0 5 g; 00 fi f listed in Table V, the following polymerization mixture grams 9 1 y e l P2 3 g was used: chloral (70 ml), p-chlorophenylisocyanate (4.2 i Suspen e m e a} We C 6 P ml.) and a one molar benzene solution of triphenylphosmixture and polymerization carried out as descnbed phine (23 To the mixture heated at C a dye g f Example A flock fined copolymer was (type and amount as shown in Table V) was added, and o tame EXAMPLE the homogeneous solution was placed in a cell formed 87 by glass plates held apart by a 3 mm. polyvinyl chloride Pigmented chloral, p-chlorophenyl isocyanate copolymers 35 spacer' P1YII1Pr1Zat19n was by Placmg the assembly and its motionless polymerization mixture in an To a mixture of 10 ml. of chloral and 0.6 ml. of p ice bath at 0 C. for 2 hours, and then held at room chlorophenylisocyanate was added at 60 C. a one molar temperature for 16 hours. Colored copolymer sheets havbenzene solution of triphenylphosphine (0.4 ml.) and ing a thickness of 3 mm. and good color stability, even 0.025 g. or 0.050 g. of the following pigments in separate 40 after heat treatment for 1 hour at 120 C. (weight loss experiments: Polychloro copper phthalocyanine, copper 8-14%), were obtained.

TABLE v Example Dye Ammg;

s9 0 NH, 0.06

s1 NH: 0.0a

n Q 0 NH;

TABLE VContlnued Amount Example Dye 93 (I) NH: 0.1

| OH CH oiN ii IL'HQ The unpolymerized liquid mixtures of chloral and the t i comonomers described above and these liquids contain- Example w ing a polymerization catalyst, aprotic solvent or filler form number Polymerization conditions apotlhler embodiment of the ilnvention. The ioncentfrizlaition at 3 0 16 a t 5%? 23,3 0 c ora comonomers, cata ysts, aprotlc so vents, ers, at a a f etc., are as described above. The liquid mixtures of iti iir i'iila t 38:2 7 3:: chlora nd com 11 me s with 'ni iator onv nient- 1hr at 0 la 0 O I out! t can c e 1 hrat -50 0., 16 hrs. atr.t 82.3 60.6

ly be stored and shipped prior to polymerization since they do not undergo polymerization in the absence of a polymerization initiator. The unpolymerized liquid mixtures containing a catalyst may be stored and shipped if they are maintained above the threshold polymerization temperature of the particular liquid. It should be understood, however, that storage times may vary from one composition to another, some being storable and shipable for longer periods of time than other. These liquid mixtures can be heated in a range whose lower limit is above their threshold temperatures and whose upper limit is below their reflux temperatures. However the temperature should not exceed the decomposition temperature of any of the ingredients of said liquid mixtures. Fillers can be added to the mixtures of monomers maintained above the threshold temperature. The filler-comonomer mixtures are in the form of a paste having a dough-like consistency which can be fabricated into shaped objects by matcheddie molding coupled with cooling the mixture below the threshold temperature.

The conversion of comonomers to polymer may be made over wide ranges of polymerization conditions.

EXAMPLE 96 Chloral, p-chlorophenyl isocyanate copolymer sheets To a mixture of 140 ml. of chloral and 9.3 ml. of p-chlorophenyl isocyanate at 50 C. was added 6.0 ml. of a 1 M solution of triphenylphosphine in benzene. The resulting uniform mixture was used to fill 3 mm. clear sheet molds (described in Example 82). The molds con- 1 Room temperature.

STABILIZATION OF POLYMERS BY HEAT TREATMENT It has been mentioned earlier that solvent and unpolymerized monomers may be removed from the copolymers of this invention by evaporation or extraction. Such treatment results in polymer of enhanced thermal stability.

The polymers may also be stabilized against thermal degradation by, surprisingly enough, a heat treatment at a temperature range of 80 to 175 C. for a period of time ranging from 5 minutes up to several hours. It is believed that the raw polymers contain stable polymer, an unstable fraction, and unchanged monomers and solvent. In order to prepare polymers having enhanced usefulness, particularly for extended use at elevated temperatures, the solvent and unchanged monomers should be removed and more importantly the less stable portion present in the polymer should be altered or removed. The heat treatment appears to remove the solvent and unchanged monomers and also results in an enhancement of the thermal stability of the polymer.

This is a most surprising phenomenon since other raw polymers, not previously treated for heat stability, such as polyvinyl chloride and polyoxymethylene decompose autocatalytically when heated and become less stable rather than more stable to heat. Samples of the copolymers of this invention that lost weight rapidly at first, 6% in the first 100 hours at 100 0., become essentially weightstable, only 0.7% loss per week, after being heated at 100 C. for 600 hours.

EXAMPLE 97 (A) Copolymer of chloral and p-chlorophenyl isocyanate A clear sheet 3 mm. thick of 95/5 mole ratio chloral/ p-chlorophenyl isocyanate, prepared according to Example 52 but omitting the glass wool, was cut into four pieces. Piece I was not treated further. Pieces II, III, and IV were 25 baked in a 120 C. air oven for 1, 2 and 6 hrs., respectively. The relative thermal stability of the four pieces at 60 was then determined by measuring the further loss in weight after 225 hrs. at 60. I lost 18.8% while II, III and IV lost only 1.5, 0.3 and 0.1% respectively.

(B) Copolymer of chloral and toluene diisocyanate A sheet like that in A was made substituting toluene diisocyanate for the p-chlorophenyl isocyanate to give a 95/5 mole ratio copolymer of chloral/toluene diisocyanate. The sheet was cut into four pieces. Piece I was not further" treated. Pieces II, III and IV were baked at 120 C. for 1, 2 and 6 hours, respectively as in (A). On aging at 60 C. for 225 hrs. I lost 14.6% while II, III, and IV lost only 0.2, 0.2 and 0.0%, respectively.

STABILIZATIOIN OF POLYMERS BY SOLVENT EXTRACTION The copolymers resulting from the cryotachensic copolymerization process can be processed in various ways in order to remove any last traces of unpolymerized monomers. For some purposes it is sufiicient merely to allow the polymerized piece to air dry whereupon the unpolymerized material spontaneously evaporates. This is illustrated for example in Examples 41 and 42. The unchanged monomers are removed somewhat more rapidly by holding the polymerized piece under reduced pressure for a period as in Examples 2 or 53. Even more eifective in removal of unchanged monomers as well as initiator residues is the process of washing or exhaustively extracting the polymer with a liquid in which the monomers are soluble but the polymer insoluble. In the case of those polymers of the present application which contain at least about 80 mol percent chloral, the choice of solvent for such an extractive procedure is quite wide since the monomers employed are generally soluble in organic liquids while the polymers are not. Unchanged chloral can be removed from the polymer with water. Such extractive procedures are illustrated in Examples 2 and 45-B.

Washing or exhaustive extraction of the copolymers of the present application with liquid is as stated above very elIecti-ve in removal of unchanged monomer but in addition washing or exhaustive extraction with certain selective solvents results in products of enhanced thermal stability and resistance to discoloration on exposure to light. Such improvements are especially desirable in end uses which involve exposure to elevated temperatures or in glazing applications where clear sheets having prolonged freedom from color development are important.

It is believed that the solvents which are especially effective in enhancing thermal stability actually do more than remove unchanged monomers and initiator residue and are in fact effective in eliminating certain thermally unstable polymer fractions from some polymer preparations. As can be seen from the examples given below solvents such as acetone or methanol for example which give polymer of enhanced thermal stability, do in fact bring about weight losses much greater than other solvents such as water or carbon tetrachloride, which do not markedly enhance thermal stability.

EXAMPLE 98 Copolymer of chloral and p-chlorophenyl isocyanate Transparent clear sheets 3 mm. thick were prepared by the general procedure of Example 52 but no glass wool was used between the plates. The monomer mixture consisted of 140 ml. of chloral and 9.3 ml. of p-chlorophenyl isocyanate. It was heated to 52 C. and 6.0 ml. of a 1- molar solution of triphenyl phosphine in benzene was added. The polymerization was eifected by cooling the uniform, quiescent polymerization mixture at C. for 1 hour. After standing overnight the resultant sheets were baked for 1 hour at 120 C. and lost about 12% in weight to give clear transparent panels essentially free of unpolymerized chloral. The sheets were cut into strips 12.5

Thermal stability,

Extrac- Percent percent tion lost on lost in 4 Extractant temp. extraction hrs. at 200 Example number: 34. 2

A None r.t. 2.0 27.1

B Water 60 C 2.4 35.2

C {r.t. 2.5 20.3

011013 Q i g r.

E Benzene "lso o. 3.; F Pentane C. at a CHzCh Lt. 17.9 1.0

I Meme --{eo o 19.3 1.5

1 Room temperature.

Improvement in color retention on outdoor exposure after solvent extraction can be seen if pieces like A above (or equivalent sheets which have been baked for 1 hr. at 120 C.) are placed on outdoor exposure in Arizona along with a solvent-extracted sample like I above. I will remain essentially colorless while A will become increasingly yellow, amber and finally red-brown.

Other effective solvents include acrylonitrile, toluene, acetonitrile, acetic acid, acetic anhydride, methyl ethyl ketone, pentane, methylene chloride, ethyl acetate, trichloroethylene, tetrahydrofuran, diethyl maleate and trimethyl borate.

STABILIZATION OF POLYMERS WITH ULTRA- VIOLET LIGHT SCREENING AGENTS The polymers of the invention can be protected against discoloration by ultraviolet irradiation by the incorporation of ultra violet screening agents. These agents can be incorporated after the polymerization process has been carried out or by adding the agent directly into the monomer mixture before polymerization is effected.

Incorporation of such screening agents or light stabilizers into the formed polymer can be accomplished by soaking the polymer in the light stabilizer or a 01-20% solution thereof in an organic solvent.

EXAMPLE 99 Copolymer of chloral and p-chlorophenyl isocyanate An acetone-extracted sample of /5 chloral-p-chlorophenyl isocyanate copolymer was allowed to soak in a 2% acetone solution of ethyl 2-cyano-3,3-diphenyl acrylate (Ph C-=C(CN)CO0Et) for 16 hours, blotted dry, heattreated for 4 hours at 120 C., and given a 30-day weather test under accelerated conditions in Arizona. No color formation was noted after the exposure. A simultaneously exposed control sample without the light stabilizer was brown after exposure.

EXAMPLE 100 Copolymer of chloral and p-chlorophenyl isocyanate A clear sheet 3 mm. thick of 95/5 mole ratio chloral/ p-chlorophenyl isocyanate copolymer like that of Example 52 was baked 1 hr. at C. and cut into strips /2 wide and 5" long. Three pieces were soaked in a 2% solution of (a) 2-(2'-hydroxy-3,5'-ditertbuylphenyl)benzotriazole available from Geigy Chem. Corp. of Ardsley, N.Y., as Tinuvin 327, (b) ethyl-2-cyano-3,3-diphenyl acrylate available from General Aniline and Film Corp., New York, NY. as Uvinul N-35 and (c) 2,2'-dihydroxy- 4,4'-dimethoxy benzophenone also available from General Aniline and Film Corp. as Uvinul D-49, A fourth piece 28 calculated. Without the diluent present the conversion of monomer to polymer was 87-89%. The presence of 20 vol. percent of diluent, based on chloral, enhances the conversion of polymer up to as much as 97%.

(d) was left untreated. On outdoor exposure (d) turned quite dark while (a), (b) and (c) remained nearly color- V01 Wt Percent 1e55- Diluent percent percent conversion In addition to the specific benzophenone, benzotriazole N mber and substituted acrylate type ultra violet screens, shown u Benzene 20 m6 9% above, other members of these three types may be used. 10 g giile t g f gfigf Examples which might be mentioned are 2-hydroxy-4- 'jjjjjjjj j: pentaie methoxy benzophenone, 2-(2-hydroxy-5-methylphenyl) benzotriazole and 2-hydroxy-4-(2-hydroxy-3-methylacryloxy)propoxybenzophenone. Other types of light stabilizers r EXAMPLE 102 are listed in Modern Plastics Encyc. and include methyl chl l, h1 h 1 i o an t copolymer salicylate, phenyl salicylate and resorcinol monobenzoate. Pl t id 3 th k d b d E 1 82) a e mo s mm. 10 as escri e in xamp e IMPROVED CONVERSION OF MONOMER T0 were heated to 45 C. and filled with a C. mixture of POLYMER 100 ml. of chloral and 6 ml. of p-chlorophenyl isocyanate The use of an aprotic liquid has been disclosed above 0 in inert diluent as indicated below and 4 ml. of l-molar as an aid in dispersing or dissolving the initiator in the triphenylphosphine in benzene. The filled plates and their chloral. Often the liquid is additionally useful in providing quiescent mixtures were held at 0 C. for 1.5 hours and enough shrinkage of the polymerized piece to permit its then overnight at room temperature. The sheets were reready removal from the mold in which the polymerization moved, weighed, baked 4 hours at 100 C., reweighed and process was carried out. 25 the conversion of monomers to polymer calculated.

Percent conversion 01 commonomers to polymer after 1 hr. at 120 Wt. percent followed by diluent in 4 hrs. at acetone Diluent (ml. added) mixture 1 120 C. extraction Number:

A None... 1.8 B Cyclohexane (51) 21.8 Benzene 21. 8 Hexane (12.5) 6. 8 Hexane (21.0) 9. 7 Hexane (32 6).. 13. 8 Hexane (42 4) 1G. 8 Hexane 0) 21. 8 Ether (25). 11. 1 .T None 1. 8 K Tetrachloroethylene (47 34.0 L. Carbon tetrachloride (470)-... 33.5 M Toluene (47.0) 22.2 N CClzFCFzCl (47.0) 32.6

Wt. percent total diluent including the 1.8% from the benzene of the initiator solution.

It has been further found that the use of certain aprotic liquids enhance the conversion of the comonomers to the copolymers, an effect which has also been observed in the homopolymerization of chloral. High conversion of stable poly-chloral and chloral copolymers is attained by carrying out the copolymerization in the presence of up to vol. percent of an inert aprotic diluent. These inert diluents are hydrocarbons such as pentane, hexane, cyclohexane, heptane, Nujol (liquid parafiinic hydrocarbons), toluene, xylene, etc.; halocarbons such as carbon tetrachloride, trichloroethylene, tetrachloroethylene, 1,1,1-trifluorododecane, trichlorotrifiuoroethane, chlorinated biphenyls (Arochlor), etc.; and ethers which are free of protonic hydrogen or groups other than ether oxygen, chlorine or fluorine, such as diethyl ether, dipropyl ether, dibutyl ether, diphenyl ether, tetrahydrofuran and the like.

EXAMPLE 101 Chloral, p-chlorophenyl isocyanate copolymer Chloral/p-chlorophenyl isocyanate monomer mixture, 95/5 mole ratio (10 ml.), was diluted with 2 ml. of the solvent indicated and heated to 48 C. a temperature which is in excess of the threshold temperature. Initiator (0.4 ml. of 1 molar triphenylphosphine in benzene) was added. The resulting homogeneous mixture was allowed to become quiescent, cooled without agitation to 0 C. and held at that temperature for 1.5 hours. After standing overnight at room temperature, the polymerized plugs were weighed, baked 1 hour at C. to remove the diluent and the unchanged monomer, reweighed and the conversion of monomer to polymer (treated at 120 C.)

As shown in Examples 101 and 102 above, copolymers form in higher conversions from monomer mixtures containing volatile diluents as compared with undiluted monomers. The same is true for monomer mixtures diluted with such nonvolatile diluents as Nujol or Aroclor. Copolymers containing such nonvolatile diluents can be isolated by baking out the unchanged chloral to leave homogeneous solids still containing the nonvolatile diluent uniformly dispersed in the chloral copolymer. By extaction with a suitable solvent such as acetone the nonvolatile diluent as well as the unchanged monomer can be removed to leave unmodified copolymer free of the diluent. In either case, conversion of monomers to copolymer is enhanced over the conversion realized in the absence of diluent.

EXAMPLE 103 (A) Copolymers of chloral and p-chlorophenyl isocyanate A homogeneous mixture of 10 ml. of chloral, 0.6 ml. of p-chlorophenyl isocyanate and 0.4 ml. of a l-molar solution of triphenylphosphine in benzene was prepared in a test tube at 55 C. The tube and its placid contents was cooled without shaking to 0 C. for 1.5 hours, held at room temperature for 16 hours, and then the resulting polymer plug was baked for 1 hour at 120 C. The conversion to polymer was 92.3%. Similar plugs to which 5 and 10% by weight of Nujol (light mineral oil) or 5 and 10% by weight of Aroclor (mixture of chlorinated biphenyls) had been added to the monomer mixture before polymerization was efiFected gave conversions to polymer of 94.9, 94.9, 93.0, and 95.7%, respectively. These plugs were homogeneous mixtures of copolymer with non- (B) Copolymers of chloral and p-chlorophenyl isocyanate In the following examples 3 mm. sheets were extracted with acetone to remove not only the unchanged monomer but also the nonvolatile diluent. The enhancement of con- 7 version by virtue of the presence of diluent during polymerization is shown.

Mixtures of 140 ml. of chloral, 9.3 ml. of p-chlorophenylisocyanate and 6.0 ml. of a 1 molar solution of triphenylphosphine in benzene at 52 C. were diluted with the amounts of Nujol or Aroclor indicated below. The

7 resulting solutions were used in the preparation of 3 mm.

clear sheets by the manner of Example 82. The filled forms were cooled to C. for 1.5 hrs. to effect polymerization. After standing overnight at room temperature each sheet was weighed, extracted with acetone for 24 mm. OD test tubes. To each was added 1.88 ml. of chloral, 0.12 ml. of p-chlorophenyl isocyanate and 8 ml. of one of the diluents specified below. Each mixture was heated to 50 C. and 0.08 ml. of a l-molar solution of lithiumtert-butoxide in cyclohexane was added to produce uniform mixtures. Polymerization was effected by cooling the mixtures under quiescent conditions to 0 C. for 1 hour. After standing at room temperature for 16 hours, the test tubes were broken away and the diluents evaporated from the gel plugs at O.1,u Hg pressure for 24 hours at room temperature.

Diluent A CCl CClF- B C Cl F C F(CF CH CH TABLE VI The following dlluents have given foam structures at the diluent/monomer ratios shown The following diluents, although closely related to those that worked, caused the gel plug collapse on evaporation of the diluent sion of monomer to polymer calculated.

Total wt.

percent Percent Example Number Diluent (g) diluent 1 conversion I. N 1.4 76.4 II Nujol (25)-.... 11.1 84.6 111---.-- Nujol (12.5)... 6.4 81.3 1V Aroclor (26).-- 11.1 80.9

' l The total weight percent of diluent in the chargeineludes not only the added Nujol or Aroelor but also the benzene introduced as solvent for the initiator.

FOAMED POLYMERS 80vol. percent of Freon 112A, 1,1-difiuorotetrachloroethane (CClgCClFg), Freon 3F, 1,2-difiuorotetrachloroethane (CCl FCCl F), and Freon 111, monofiuoropenta- "chloroethane (0201511 These compounds are'relatively high-melting compounds, melting at 40, 26 and 100 C., respectively. They boil at 91.5, 92, and 137 C.,respectively. The monomer-Freon solution is cooled to effect polymerization and then the Freon is removed in vacuo V at room temperature. The fluorocarbons may be present in the polymer as solids or liquids. Chloral copolymer foams of this invention prepared with these fluorocarbons resist collapse when the fluorocarbon is evaporated 01f.

. EXAMPLE 104 Copolymers of chloral and p-chlorophenyl isocyanate The following polymerizations were carried out in 15 Dlluent B.P., C. M.P., C. No foam at- F113 CO1 F0011 4s 35 6 1 to 1 1. F214 CsCl4F4 112 471. I

CFMCHQ) 0011. 214 4/1 hrs., dried in vacuo at 60 C., reweighed and the conver- INITIATORS The following examples illustrate a number of additional suitable initiators and their method of preparation.

EXAMPLE Tertiary phosphine chloral reaction products (A) (C H P/CCl CHO 1/1 salt: The salt for which H. Holfman and H. I. Diehr in Tetrahedron Letters, 13, 583 (1962) suggested the structure and which we have substantiated, was prepared as folows:

A solution of 52 g. of triphenyl phosphine in 200 ml. of dry ether was heated to reflux with stirring under dry nitrogen. As a solution of 25 ml. of chloral in 50 ml. of dry ether was added, a white precipitate separated with evolution of heat. The addition required about 10 min. The ether was removed by evaporation in a stream of dry nitrogen overnight at room temperature to leave 78 g. of triphenyldichlorovinyloxyphosphonium chloride. A

portion (76 g.) of the product was dissolved under dry nitrogen in about 300 m1. of dichloromethane and filtered under dry nitrogen to remove about 4 g. of insoluble material. The filtrate was evaporated to about 250 ml. and diluted with about 100 ml. of petroleum ether. When only an oil separated, the mixture was evaporated to about 200 ml. and then mixed with about 100 ml. of dry diethyl ether. The colorless crystals which formed were collected on a filter under nitrogen and dried to give 48 g. of pure triphenyldichlorovinyloxyphosphonium chloride, M.P. -132 C. (dec.).

Analysis.-Calcd. for C H OCl P (percent): C, 58.63; H, 3.94; CI, 25.96; P, 7.56. Found (percent): C, 58.31; H, 3.99; CI, 25.46; P, 7.47.

Tertiary phosphine/bromal reaction product obtained weighed 54 g. and boiled at 145 C. at 0.1 mm. 145 C. at 0.1 mm.

Analysis.-Calcd. for C H OP (percent): C, 77.69; H, 5.43; P, 1.13. Found (percent): C, 76.74; H, 5.51; P, 10.89.

(B) Diphenyl phenylphosphonite, C H P(OC H To a solution of phenol (38.0 g.) and pyridine (32 g.) in 100 ml. of dry ether was added at 10 C. a solution of phenylphosphonous acid dichloride, C H PCl (35.8 g.) in 50 ml. of dry ether. After 1 hr. at C., the pyridinium chloride was removed by filtration and the filtrate distilled. The main fraction (33 g.) of diphenyl phenylphosphonite boiled at 170 C. at 0.8 mm.

Analysis Yield, g. Found Calculated Chloral, (percent M.P., G.

m1. of theory) (dec.) 0 H P 01 O H P Cl (D) Triisopropylphosphine/chloral 1/3 product: To chloral (200 ml.) heated to 60 C. under nitrogen was added 11.5 g. of triisopropyldichlorovinyloxy-phosphonium chloride (from C-3 above). The clear solution was held overnight under nitrogen at 60 C. and then poured into 400 ml. of dry ether. The oil which first separated became crystalline on standing at room temperature. The solid was collected under nitrogen and recrystallized by dissolution in 80 ml. of dichloromethane and dilution with 400 ml. of dry ether. The crystalline 3/1 chloral/ triisopropylphosphine reaction product was collected and dried under dry nitrogen.

Analysis.Calcd. for C H; O Cl P (percent): C, 29.90; H, 4.01; P, 5.14; CI, 52.97. Found (percent): C, 30.47; H, 4.29; P, 5.16; Cl, 52.92.

EXAMPLE 106 Triphenylphenoxyphosphonium phenoxide s 5)3 6 5] e 5 To a solution of triphenyl dichlorophosphorane (C H PCl (33.3 g.) in 350 ml. of benzene was added at 5 C. 20.2 g. of triethyl amine in 40 ml. of benzene followed by a solution of phenol (18.8 g.) in 80 ml. of benzene. The mixture was held at 0 C. for 0.5 hr. and at room temperature overnight. The triethylammonium chloride was removed by filtration. Evaporation of the benzene left a semicrystalline residue which when treated with a mixture of cyclohexane, acetone and ether deposited 8 g. of crystalline triphenylphenoxyphosphonium phenoxide which when unionized can be called triphenyldiphenoxyphosphorane.

Analysis.Calcd. for C H PO (percent): C, 80.34; H, 5.62; P, 6.91. Found (percent): C, 77.08; H, 5.74; P, 6.79.

EXAMPLE 107 Arylaryloxy tertiary phosphines and their sulfur analogs (A) Phenyl ester of diphenylphosphinous acid,

(C5H5)2POC6H5:

Diphenylphosphinous acid chloride [(C C H PCl, 55 g.] was added to a solution of phenol (21.6 g.) and pyridine (18 g.) in 250 ml. of dry ether at 5 C. with stirring. After standing overnight, the precipitated pyridinium chloride was removed by filtration and the filtrate distilled. The phenyl ester of diphenylphosphinous acid l( s 5) z s sl Analysis.Calcd. for C H PO (percent): C, 73.46; H, 5.14; P, 10.53. Found (percent): C, 73.38; H, 5.39; P, 10.37.

(C) p-Tolyl ester of diphenylthiophosphinous acid, p-CH C H SP(C H To a solution of p-methylthiophenol, p-CH C H SH (12.6 g.) and pyridine (7.2 g.) in ml. of dry ether was added at 5 C. diphenylphosphinous acid chloride (C H PCl (18 ml.). The precipitated pyridinium chloride was removed by filtration and the filtrate distilled to give 26 g. of p-tolyl diphenylthiophosphinite, p-CH C H SP(CH boiling at C. at 0.5 mm.

Analysis.--Calcd. for C H PS (percent): P, 10.04; S, 10.40. Found (percent): P, 9.89; S, 11.04.

(D) Di-p-tolyl phenylthiophosphonite,

To a solution of pmethylthiophenol p-CH C H,SH (38 g.) and pyridine (22 ml.) in 100 ml. of dry ether was added at 10 C. a solution of phenylphosphonous acid dichloride, C H PCl (27.0 g.) in ether (50 ml.). After 1 hour, the pyridinium chloride was removed by filtration and the filtrate distilled to give 46 g. ofdi-p-tolyl phenylthiophosphonite (p-CH C H S) PC H boiling'at C. at 0.4 mm.

Analysis.Calcd. for C H PS (percent): C, 67.77; H, 5.40; P, 8.74; S, 18.09. Found (percent): C, 68.16;v H, 5.66; P, 8.80; S, 18.09.

EXAMPLE 108 Substituted tertiary aryl phosphines A variety of trisubstituted phosphines were prepared by adding an ethereal solution of PCl C H PCl or (C H PCl to an ethereal solution containing 3, 2, or l mole, respectively, of an appropriately substituted phenyl Grignard reagent, or in certain cases, the analogous organolithium derivative. The reaction mixture was bydrolyzed with an excess of aqueous ammonium chloride, the organic layer separated and dried over anhydrous magnesium sulfate. Evaporation ofthe ether. left the desired tertiary phosphine which was appropriately distilled or recrystallized depending on its physical properties.

'lIhe phosphine initiators made in'this way are tabulated be ow.

(A) Tri-p-chlorophenylphosphine (p -Cl-C H P: The Grignard reagent from 200 g. p-chloroiodobenzene and 20.8 g. of magnesium was reacted with 15.8 ml. phosphorous trichloride to give 39 g. tri(chlorophenyl)phos- 33 phine, B.P. 228 C. at 1 mm., M.P. 103.5 C. ex ethanol.

(B) p-Methoxyphenyldiphenylphosphine (cs sh e a a'p The Grignard reagent from 59 g. o-iodoanisole and 7.3 g. magnesium was reacted with 44 g. of diphenylphosphinous chloride to give 41 g. of diphenyl-omethoxyphenylphosphine, M.P. 122-123 C. ex alcohol.

An'alysis.--Calcd. for C H PO (percent): C, 78.08; H, 5.86; U, 10.60. Found (percent): C, 78.00; H, 5.99; P, 10.24.

(E) Tetramesityldiphosphine The Grignard reagent from 120 g. mesityl bromide and 17.5 g. magnesium was reacted with 20.6 g. phosphorus trichloride to give 27g. of what is apparently tetramesityldiphosphine, M.P. 240-244 C. (dee.) ex ether.

(F) Mesityldiphenylphosphine The Grignard reagent from 50 g. mesityl bromide and 7.3g. of magnesium was reacted with 44 g. of diphenylphosphinous chloride to give 28.6 g. of diphenylmesitylphosphine, B.P. 175 C. at 0.2 mm.

Analysis.-Calcd. for C H P (percent): C, 82.87; H,

6.96; P, 10.18. Found (percent): C, 81.82; H, 6.96; P,

(G) Tri(o-meththiomethylphenyl)phosphine The organolithium compound from 118 g. o-bromobenzyl methyl sulfide (oBrC H CH SCH and 380 ml. of a hexane solution containing an equivalent amount of butyllithium was reacted with 16 ml. phosphorous trichloride to give 6 g. of solid tri(o-meththiomethylphenyl) phosphine, M.P. 89-90" C.

Analysis.-Calcd. for C H PS (percent): C, 65.12; H, 6.15; P, 7.00; S, 21.73. Found (percent): C, 65.48; H, 6.33; P, 7.39; S, 20.37.

(H) Diphenyl-o-meththiomethylphenylphosphine,

The organolithium derivative from 21.7 g. of o-bromobenzyl methyl sulfide (o-BrC H CH SCH and 75 ml. of a 1.6 molar hexane solution of butyllithium was reacted with 18 ml. of diphenylphosphonous chloride to give liquid diphenyl o-meththiomethylphenylphosphine.

Analysis.-Calcd. for C H PS (percent): C, 74.51; H, 5.94; P, 9.61; S, 9.95. Found (percent): C, 74.35; H, 6.03; P, 9.30; S, 9.56. 1

' EXAMPLE 109 Triarylaryloxy (or thio) phosphonium halides (A) p-Methylphenylthiotriphenylphosphonium bromide, p-CH C H SP (C H Br-: To a suspension of 12.3 g. of the triphenylphosphinel-cyanogen bromide reaction product in ml. of benzene at 5-10" C. was added 4.2 g. of pmethyl' thiophenol in 15 ml. of benzene to give a clear solution which was then held at 45 C. for 15 minutes. Evaporation of the benzene in vacuo at room temperature left p-methylphenyl-thiotriphenylphosphonium bromide as an oil which turned crystalline on standing at room temperature.

Analysis.-Calcd. for C H PBrS (percent): P, 6.66; S, 6.89. Found (percent): P, 5.61; S, 7.19.

(B) p-Methylphenylthiotriphenylphosphonium chloride, p-CH C H SP(C H Cl": To a suspension of 10.8 g. of the triphenylphosphine/ cyanogen chloride reaction product, C H P(CN)Cl in 100 ml. of benzene at 510 C. 'was added a solution of 4.2 g. of p-methyl-thiophenol in 15 ml. of benzene. After addition was complete, the clear solution was held at 45 C. for 20 minutes. The benzene was removed in vacuo at room temperature to leave p-methylphenylthiotriphenylphosphonium chloride.

Analysis.Calcd. for C H PClS (percent): P, 7.36; S, 7.62. Found (percent): P, 7.15; S, 7.82.

(C) Phenoxytriphenylphosphonium bromide,

To a suspension of 12.3 g. of the triphenylphosphine/ cyanogen bromide reaction product (C H P(CN)Br in 100 ml. of benzene was added at 5-10 C. a solution of 3.1 g. of phenol in 15 ml. of benzene. The suspension was then held at 40 C. for 20 min. before collecting the phenoxytriphenylphosphonium bromide on a filter as a. white solid.

Analysis.-Calcd. for C H POBr (percent): P, 7.12; Br, 18.36. Found (percent): P, 6.41; Br, 23.13.

(D) Phenoxytriphenylphosphonium chloride,

To a suspension of 10.8 g. of the reaction product from triphenylphosphine and cyanogen chloride in 100 m1. of benzene was added with cooling a solution of 3.1 g. of phenol in 15 m1. of benzene. The mixture was heated to 45 C. for 20 minutes and then cooled. The solid phenoxytriphenylphosphonium chloride was collected, washed with benzene and then pentane and dried to give 12.9 g. of product.

(E) Phenoxydiphenylmethylphosphonium iodide,

To a solution of 10.5 g. of phenyl diphenylphosphinite (from Ex. 107-A) in 30 ml. of dry ether was added 2.38 ml. of methyl iodide. After standing 3 days at room temperature, the suspended solid reaction product was collected on a filter and dried to give 9.7 g. of phenoxydiphenylmethylphosphonium iodide, M.P. 151-153 C. (dec.).

Analysis.-Calcd. for C H POI (percent): P, 7.37; I, 30.20. Found (percent): P, 7.33; I, 30.40.

ADDITIONAL POLYMERS The following examples are additional illustrations of the preparation of the polymers of the invention.

EXAMPLE 110 Copolymers of chloral and p-chlorophenyl isocyanate In each of a series of test tubes a mixture of 15.11 g. of chloral and 0.6 ml. of p-chlorophenylisocyanate was heated to 55 C. under a blanket of dry nitrogen before adding 0.2 g. of initiator to produce a homogeneous mixture. After 5 to 10 minutes at 55 C. during which time no polymerization occurred, the tubes with their contents were placed under quiescent conditions in a 0C. bath for 1.5 hour and held at room temperature overnight. A solid plug of copolymer was formed in each 35 case. The plugs were heated for 1 hour at 120 C. and the weight loss noted.

36 percent of unchanged chloral still present. Alternately, it was (1) allowed to air dry, (2) baked (for example for 1 hour at 120 C.) in air, (3) baked as in (2) followed by E ti t Initiator P rcg t i t soaking or continuous extraction in a solvent for the un- 55%,? structure Example r 5 changed chloral (acetone, methanol, water, chlorinated hydrocarbons, hydrocarbons, etc.), or (4) directly (with- 1,3335? [(CHmCHhP' 10H) out baking) soaked or continuously extracted in such 3-- gtgl sggo grei 13? A 2-3 solvents. The solvent extracted sheets resulting from (3) 1: afij f fi j 1074; or (4) were taken dried in vacuo at 50-60 C. until all e sh r flm-p 107-0 traces of the solvent had been removed. The results are F o.H.P so.H.oH.-p). 107-D 13.6 10 d th bl b 1 G (C.H6)zPG.H.oOH,- 108 summarize m e ta e e ow.

O-CHaOCoHMCoHW 108-1) (B) A mixture of 140 ml. of freshly distilled chloral [(2,4,6-(CH3)3C0H7)2P]2 108-131 17.2 d 9 3 1 h h 1 95/5 1 t. 1034 an m p-c orop eny isocyanate mo ar ra 0) g fi g g l g H) Egg g-g was heated to 52 C. under nitrogen. A l-molar solution gi g f sd yg; 1 (6.0 ml.) of the U1 triisopropylphosphine/chloral salt 9 CHaCvESPWrHOFCl 109-13 8 [of Example 105-C(3)] in chloroform was added and the CsH5OP CcHsXFBl 109C 10.6 ul l d .b d b 1 o.H.oP c,H, ,+c 109.1) 20.26 res ting so ution was used as escri e a ove (Examp e di t g%(%h )g a 3-: 111-A) to prepare a 3 mm. sheet. After the polymerized EEI ;H; 7) 814. sheet had been after-treated as in Example 111-A(4) by Br( H:)aP(C +131 26.2 one extraction there was obtained a clear colorless nowmnmohfiaor- 32.3 T Th h f l (C5H17)zPCH3 (CH3O)zPO3- s eet in 73 0 conversion. e s eet was use u as a trans- (gfl z 7 parent glazing panel. a Il5ty 1m rphoflne 2) 644:2 The following examples illustrate the use of many of Z Pyridine the initiators for the preparation of 3 mm. sheets of 1 Initiator 0.24 g.)/monomer mixture held roi- 1 hour at 60 0. before p y mole ratlo chloral/p-chlorolghenyl f g i n b1 cyanate) following the general precedure outlined above a 1.3..;% &o;f8ip m%ho added at 65 0. in section A and the amounts of reagent given in section After 24 hr. at 100 C. B.

Percent conversion following after Initiator treatments of example Ill-A Ex. Structure Example 1 2 31 41 47 43 C..... CsHDzPOCH=COlz CP 89. D-- cHa)7P00H=cc1i+01- 65.3 E CzHQ PO o H=C o1+7c1 73, 9 F- (i-C H POCH=CCh+Cl' 85.4 G. (n-C4He)aP0 0H=o clrcl- 77.1 H (t-C4H )POGH=CC1z Cl" see I (cyc1o-O H11)3POCH=C CIFCI" 78. 0 J (O6Hl5)3POCH=CBH Br 75.0 K. (C|H5)3PO12 73.1 L- (D-CIC'HOBP 79.7 M- (C|H5)2POC0H| 88.8 N.-- 12 297 83.2

C2 s)4N*C1" 52 seas. 6 l5 3 R l----E U B)ZP( I)I I I)I BL.-- COHlP(C3H5)l l Acetone as extraetant. l Chloral as extractant. i Carbon tetrachloride as extractant. l Commercially available. I Initiator (0.4 mole percent) added to 80 ml. chloral and 4.96 ml. p-ClC H|NCO at 65 C. After 24 hr. at 100 C.

EXAMPLE 111 EXAMPLES 112-117 sheets of copolymers (A) General procedure: For the purpose of preparing a clear, transparent sheet, a 3 mm. thick mold was prepared from two sheets of glass (180 mm. x 280 mm.) and a length of 6 mm. OD x 1.5 mm. wall gum rubber tubing as described in Example 52, but no glass wool was used between the plates. A mixture of freshly distilled chloral with the desired amount of a suitable comonomer and, if desired, an inert diluent was heated under a blanket of dry nitrogen to a temperature in excess of the polymerization threshold temperature commonly in the range of 65 C., before the initiator was added and allowed to mix. After the initiated mixture was homogeneous, it was used to fill the mold which had been preheated to at least the temperature of the initiated monomer. The filled mold was then cooled under quiescent conditions, usually in a 0 C. bath, for long enough to complete the polymerization; commonly 1.0 to 1.5 hours. After warming to room temperature overnight, the polymerized sheet was after-treated in various ways to remove the few Chloral/p-chlorophenyl isocyanate copolymers In each of the following examples the indicated amounts of chloral and p-chlorophenyl isocyanate were combined and to this solution was added 0.2 ml. of dimethylformamide and 0.8 ml. of acetonitrile. The resulting solution was heated to 50 C. and thoroughly mixed with the amount of initiator solution (1 molar lithium chloride in dimethylformamide) indicated. The quiescent mixture was then cooled without agitation to the temperature shown for the period indicated. The resulting polymerizate was dissolved in toluene. The solution was clarified by filtration and the filtrate poured into a large excess of methanol to precipitate the chloral/p-chlorophenyl isocyanate copolymer. After being washed thoroughly with methanol, the product was dried, weighed, and analyzed for nitrogen content, from which the mole percent of groups and chloral groups in the copolymer was calculated.

Example 112 113 114 115 116 117 Chloral (ml 5 6.5 5.4 3.4 2.5 1.6 -ClCH NCO (m1) 3.6 4.2 6.2 8.6 9.8 11.0 Pnitiatoflml 0.27 0.2 0.27 0.27 0.27 0.3 rs. at 1 1 2 2 2 0 Hrs. at room temp 16 16 16 16 16 16 G. Copolymer 7.5 13 12.0 9.7 7.7 4.8 PercentNin copolymer 3.44 3.51 3.84 4.33 4.86 4.94 Mole percent isocyanate in copolymer 36.5 87.5 41.1 46.5 52.3 53.1 Mole percent ehloralin copo1ymer.- 63.6 62.5 58.9 53.5 47.7 46.9

EXAMPLE 118 Chloral/phenyl isocyanate copolymer To a solution of 9 ml. of phenyl isocyanate and 1 ml. of chloral in 30 ml. of dimethylformamide (freshly distilled ofi P 0 at 25 C. was added 2.0 ml. of a saturated solution of sodium cyanide in dry dimethylformamide. After the initiator solution was thoroughly mixed with the solution of monomers, the quiescent mixture was cooled without agitation to --50 C., held at 25 C. overnight, and then allowed to warm to room temperature. The resulting polymer solution was poured into a large volume of methanol to precipitate the polymer, which was washed thoroughly with methanol and dried to give 1.9 g. of chloral/phenyl isocyanate copolymer. The product was found to contain 5.04, 5.05 weight percent of nitrogen, which corresponds to 47.5 mole percent of units and 52.5 mole percent of chloral units in the polymer. The polymer was soluble in chloroform.

EXAMPLE 119 The procedure of Example 118 was repeated using 9.5 ml. of phenyl isocyanate and 0.5 ml. of chloral. There was obtained 1.2 g. of chloroform-soluble copolymer having 5.65, 5.67 weight percent of nitrogen (53.5 mole percent of combined phenyl isocyanate units and 46.5 mole percent of chloral units).

Several of the process and product modifications shown in this specification are applicable in the preparation and modification of chloral homopolymers of the type shown in my US. Pat. 3,454,527.

It has been noted above that the conversion of chloral to its homopolymer is enhanced when aprotic liquids such as hydrocarbons, halocarbons and ethers are present during polymerization. Chloral homopolymer may further be stabilized by heat treatment as in Example 97, by solvent extraction as in Example 98, and by incorporation of ultraviolet light screen agents as in Examples 99 and 100. Polychloral can be prepared in foam or sponge form by following the procedures of Example 104. The initiators shown in Examples 105 to 111 are also suitable for effecting the cryotachensic homopolymerization of chloral.

I claim:

1. An addition copolymer of chloral and at least one comonomer of the formula R -N=C=X wherein X is selected from the group consisting of oxygen and sulfur; R is a non-substituted hydrocarbyl radical selected from the group consisting of alkyl containing from 1 to 18 carbons, cycloalkyl containing from 1 to 18 carbons, aryl containing from 6 to 18 carbons, alkaryl containing from 7 to 24 carbons and aralkyl containing from 7 to 24 carbons, the copolymer containing from 1 to 99.9 mol percent of chloral.

2. A copolymer of claim 1 in which the comonomer is an isocyanate.

3. A copolymer of claim 1 in which the comonomer is an isothiocyanate. I

4. A copolymer of claim 1 in the form of an article of manufacture.

5. A copolymer of claim 1 in the form of a film.

6. A copolymer of claim 1 in the form of a fiber.

7. A copolymer of claim 1 in the form of a sheet.

8. A copolymer of claim 1 in the form of a pipe.

9. A copolymer of claim 1 containing an inorganic filler.

10. A copolymer of claim 1 stabilized against weight loss from heat.

11. A copolymer of claim 1 containing from about 50 to 99.9 mol percent of chloral.

12. A copolymer of claim 1 in which the comonomer is phenyl isocyanate.

13. A copolymer of claim 1 containing from about to 99.9 mol percent of chloral.

14. A copolymer of claim '1 wherein the comonomer is phenyl isocyanate.

15. A copolymer of claim 1 wherein the comonomer is methyl isocyanate.

16. A copolymer of claim 1 wherein the comonomer is ethyl isocyanate.

17. A copolymer of claim 1 wherein the comonomer is n-butyl isocyanate.

18. A copolymer of claim 1 wherein the comonomer is phenyl isothiocyanate.

19. The cryotachensic polymerization process of making a copolymer of claim 1 comprising forming, at a temperature above its threshold polymerization temperature,

a quiescent homogeneous mixture of the monomers and an effective amount of an anionic polymerization initiator,

cooling the quiescent mixture below its threshold polymerization temperature to effect polymerization of the monomers,

and maintaining the mixture quiescent during the polymerization process.

20. The process of claim 19 carried out in the presence of an aprotic solvent which is inert to the monomers and initiator and is liquid at the polymerization temperature.

21. The process of claim -19 wherein the aprotic solvent is a hydrocarbon.

22. The process of claim 19 wherein the aprotic solvent is a halogenated hydrocarbon.

23. The process of claim 19 wherein the process is carried out in a mold to produce a shaped copolymer.

24. The cryotachensic polymerization process of making a copolymer of claim -1 comprising forming, at a temperature above its threshold polymerization temperature,

a quiescent homogeneous mixture of chloral and an effective amount of an anionic polymerization initiator,

cooling the quiescent mixture below its threshold polym erization temperature to eifect homopolymerization of part of the chloral under quiescent conditions, and then adding the at least one comonomer as set out in claim 1 and causing it to copolymerize with at least the remaining free chloral.

25. The process of claim 24 in which about 60 percent of the original quantity of chloral is polymerized to homopolymer under quiescent conditions.

26. An unpolymerized liquid mixture of chloral and at least one comonomer of the formula R N=C=X wherein X is selected from the group consisting of oxygen and sulfur; R is a non-substituted hydrocarbyl radical selected from the group consisting of alkyl containing from 1 to 18 carbons, cycloalkyl containing from 1 to 18 carbons, aryl containing from 6 to 18 carbons, alkaryl containing from 7 to 24 carbons and aralkyl containing from 39 7 to 24 carbons, the copolymer containing from 1 to 99.9 mol percent of chloral.

27. A liquid mixture of claim 26 containing from about 50 to 99.9 mol percent of chloral.

28. A liquid mixture of claim 26 containing from about 80 to 99.9 mol percent of chloral.

279. A liquid mixture of claim 28 containing 0.001 to 10% by weight of the combined weight of chloral and comonomer(s) present, of an anionic polymerization initiator, said unpolymerized liquid mixture being maintained above its threshold polymerization temperature.

30. A liquid mixture of claim 28 containing 0.01 to 70% by weight of an inorganic filler.

31. A liquid mixture of claim 28 containing phenyl isocyanate as a comonomer.

32. The process of claim 19 in which a comonomer is an isocyanate.

40 References Cited UNITED STATES PATENTS 3,265,665 8/1966 Mantell et a1 26067T N 3,277,058 10/ 1966 Bastian 26067T N 3,454,527 7/ 1969 Vogl 26067 R US. Cl. X.R.

117-124 E, 126 GR, 137; 260-2.5 F, 29.2 TN, 30.4 N, 31.2 N, 31.8 S, 31. F, 32.4, 32.8 N, 33.2 R, 33.6 F, 33.6 UB, 33.8 F, 33.8 UB, 37 N, 37 P, 45.8 A, 45.8 NZ, 45.9 P, 64, 67 R, 6 S, 96 R, 598 

